1
|
Liang Y, Li F, Cui X, Lv T, Stampfl C, Ringer SP, Yang X, Huang J, Zheng R. Toward stabilization of formamidinium lead iodide perovskites by defect control and composition engineering. Nat Commun 2024; 15:1707. [PMID: 38402258 PMCID: PMC10894298 DOI: 10.1038/s41467-024-46044-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2023] [Accepted: 02/08/2024] [Indexed: 02/26/2024] Open
Abstract
Phase instability poses a serious challenge to the commercialization of formamidinium lead iodide (FAPbI3)-based solar cells and optoelectronic devices. Here, we combine density functional theory and machine learning molecular dynamics simulations, to investigate the mechanism driving the undesired α-δ phase transition of FAPbI3. Prevalent iodine vacancies and interstitials can significantly expedite the structural transition kinetics by inducing robust covalency during transition states. Extrinsically, the detrimental roles of atmospheric moisture and oxygen in degrading the FAPbI3 perovskite phase are also rationalized. Significantly, we discover the compositional design principles by categorizing that A-site engineering primarily governs thermodynamics, whereas B-site doping can effectively manipulate the kinetics of the phase transition in FAPbI3, highlighting lanthanide ions as promising B-site substitutes. A-B mixed doping emerges as an efficient strategy to synergistically stabilize α-FAPbI3, as experimentally demonstrated by substantially higher initial optoelectronic characteristics and significantly enhanced phase stability in Cs-Eu doped FAPbI3 as compared to its Cs-doped counterpart. This study provides scientific guidance for the design and optimization of long-term stable FAPbI3-based solar cells and other optoelectronic devices through defect control and synergetic composition engineering.
Collapse
Affiliation(s)
- Yuhang Liang
- School of Chemical and Biomolecular Engineering, The University of Sydney, Sydney, NSW 2006, Australia.
- School of Physics, The University of Sydney, Sydney, NSW, 2006, Australia.
| | - Feng Li
- School of Physics, The University of Sydney, Sydney, NSW, 2006, Australia.
| | - Xiangyuan Cui
- School of Aerospace, Mechanical and Mechatronic Engineering, The University of Sydney, Sydney, NSW, 2006, Australia.
| | - Taoyuze Lv
- School of Physics, The University of Sydney, Sydney, NSW, 2006, Australia
| | - Catherine Stampfl
- School of Physics, The University of Sydney, Sydney, NSW, 2006, Australia
| | - Simon P Ringer
- School of Aerospace, Mechanical and Mechatronic Engineering, The University of Sydney, Sydney, NSW, 2006, Australia
| | - Xudong Yang
- State Key Laboratory of Metal Matrix Composites, Shanghai Jiao Tong University, Shanghai, 200240, China
- Center of Hydrogen Science, School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China
- Zhangjiang Institute for Advanced Study, Shanghai Jiao Tong University, Shanghai, 201210, China
| | - Jun Huang
- School of Chemical and Biomolecular Engineering, The University of Sydney, Sydney, NSW 2006, Australia.
| | - Rongkun Zheng
- School of Physics, The University of Sydney, Sydney, NSW, 2006, Australia.
| |
Collapse
|
2
|
Tegg L, Breen AJ, Huang S, Sato T, Ringer SP, Cairney JM. Characterising the performance of an ultrawide field-of-view 3D atom probe. Ultramicroscopy 2023; 253:113826. [PMID: 37573667 DOI: 10.1016/j.ultramic.2023.113826] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2023] [Revised: 07/16/2023] [Accepted: 07/28/2023] [Indexed: 08/15/2023]
Abstract
The CAMECA Invizo 6000 atom probe microscope uses ion optics that differ significantly from the local electrode atom probe (LEAP). It uses dual antiparallel deep ultraviolet lasers, a flat counter electrode, and a series of accelerating and decelerating lenses to increase the field-of-view of the specimen without reducing the mass resolving power. In this work we characterise the performance of the Invizo 6000 using three material case studies: a model Al-Mg-Si alloy, a commercially-available Ni-based superalloy, and a Zr alloy, using a combination of air and vacuum-transfer between instruments. The ion optics of the Invizo 6000 significantly increase the field-of-view compared to the same specimen on a LEAP 4000 X Si. We also observe a significant increase in specimen yield, especially for the Zr alloy. These results combine to make the Invizo 6000 well-suited to research projects requiring large analysis volumes, particularly so for traditionally difficult samples such as oxides.
Collapse
Affiliation(s)
- Levi Tegg
- School of Aerospace, Mechanical and Mechatronic Engineering, The University of Sydney, Camperdown, NSW 2006, Australia; Australian Centre for Microscopy and Microanalysis, The University of Sydney, Camperdown, NSW 2006, Australia.
| | - Andrew J Breen
- School of Aerospace, Mechanical and Mechatronic Engineering, The University of Sydney, Camperdown, NSW 2006, Australia; Australian Centre for Microscopy and Microanalysis, The University of Sydney, Camperdown, NSW 2006, Australia
| | - Siyu Huang
- School of Aerospace, Mechanical and Mechatronic Engineering, The University of Sydney, Camperdown, NSW 2006, Australia; Australian Centre for Microscopy and Microanalysis, The University of Sydney, Camperdown, NSW 2006, Australia
| | - Takanori Sato
- Australian Centre for Microscopy and Microanalysis, The University of Sydney, Camperdown, NSW 2006, Australia
| | - Simon P Ringer
- School of Aerospace, Mechanical and Mechatronic Engineering, The University of Sydney, Camperdown, NSW 2006, Australia; Australian Centre for Microscopy and Microanalysis, The University of Sydney, Camperdown, NSW 2006, Australia.
| | - Julie M Cairney
- School of Aerospace, Mechanical and Mechatronic Engineering, The University of Sydney, Camperdown, NSW 2006, Australia; Australian Centre for Microscopy and Microanalysis, The University of Sydney, Camperdown, NSW 2006, Australia.
| |
Collapse
|
3
|
Ding X, Cui X, Tseng LT, Wang Y, Qu J, Yue Z, Sang L, Lee WT, Guan X, Bao N, Sathish CI, Yu X, Xi S, Breese MBH, Zheng R, Wang X, Wang L, Wu T, Ding J, Vinu A, Ringer SP, Yi J. Realization of High Magnetization in Artificially Designed Ni/NiO Layers through Exchange Coupling. Small 2023:e2304369. [PMID: 37715070 DOI: 10.1002/smll.202304369] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2023] [Revised: 08/23/2023] [Indexed: 09/17/2023]
Abstract
High-magnetization materials play crucial roles in various applications. However, the past few decades have witnessed a stagnation in the discovery of new materials with high magnetization. In this work, Ni/NiO nanocomposites are fabricated by depositing Ni and NiO thin layers alternately, followed by annealing at specific temperatures. Both the as-deposited samples and those annealed at 373 K exhibit low magnetization. However, the samples annealed at 473 K exhibit a significantly enhanced saturation magnetization exceeding 607 emu cm-3 at room temperature, surpassing that of pure Ni (480 emu cm-3 ). Material characterizations indicate that the composite comprises NiO nanoclusters of size 1-2 nm embedded in the Ni matrix. This nanoclustered NiO is primarily responsible for the high magnetization, as confirmed by density functional theory calculations. The calculations also indicate that the NiO clusters are ferromagnetically coupled with Ni, resulting in enhanced magnetization. This work demonstrates a new route toward developing artificial high-magnetization materials using the high magnetic moments of nanoclustered antiferromagnetic materials.
Collapse
Affiliation(s)
- Xiang Ding
- School of Transportation and Logistics Engineering, Wuhan University of Technology, Wuhan, 430063, China
| | - Xiangyuan Cui
- School of Aerospace Mechanical & Mechatronic Engineering and Australian Centre for Microscopy & Microanalysis, The University of Sydney, Sydney, NSW, 2006, Australia
| | - Li-Ting Tseng
- School of Materials Science and Engineering, UNSW, Sydney, NSW, 2052, Australia
| | - Yiren Wang
- School of Materials Science and Engineering, Central South University, Changsha, 410083, P. R. China
| | - Jiangtao Qu
- School of Physics, The University of Sydney, Sydney, NSW, 2006, Australia
| | - Zengji Yue
- Institute of Photonic Chips, University of Shanghai for Science and Technology, Shanghai, 200093, P. R. China
| | - Lina Sang
- School of Integrated Circuit Science and Engineering, Tianjin Key Laboratory of Film Electronic & Communication Devices, Tianjin University of Technology, Tianjin, 300384, P. R. China
| | - Wai Tung Lee
- Science Directorate, European Spallation Source Partikelgatan 2, Lund, 224 84, Sweden
| | - Xinwei Guan
- Global Innovative Center for Advanced Nanomaterials, School of Engineering, University of Newcastle, Callaghan, NSW, 2308, Australia
| | - Nina Bao
- Department of Materials Science and Engineering, National University of Singapore, Singapore, 1192690
| | - C I Sathish
- Global Innovative Center for Advanced Nanomaterials, School of Engineering, University of Newcastle, Callaghan, NSW, 2308, Australia
| | - Xiaojiang Yu
- Singapore Synchrotron Light Source, National University of Singapore, Singapore, 119260
| | - Shibo Xi
- Institute of Chemical and Engineering Science, Agency for Science, Technology and Research (A*STAR), 1 Pesek Road, Jurong Island, Singapore, 627833
| | - Mark B H Breese
- Singapore Synchrotron Light Source, National University of Singapore, Singapore, 119260
| | - Rongkun Zheng
- School of Physics, The University of Sydney, Sydney, NSW, 2006, Australia
| | - Xiaolin Wang
- Institute for Superconducting and Electronic Materials, Australian Institute for Innovative Materials, University of Wollongong, Wollongong, NSW, 2500, Australia
- ARC Centre of Excellence in Future Low-Energy Electronics Technologies (FLEET), University of Wollongong, Wollongong, NSW, 2500, Australia
| | - Lan Wang
- School of Physics, Hefei University of Technology, Hefei, 230009, P. R. China
| | - Tom Wu
- School of Materials Science and Engineering, UNSW, Sydney, NSW, 2052, Australia
| | - Jun Ding
- Department of Materials Science and Engineering, National University of Singapore, Singapore, 1192690
| | - Ajayan Vinu
- Global Innovative Center for Advanced Nanomaterials, School of Engineering, University of Newcastle, Callaghan, NSW, 2308, Australia
| | - Simon P Ringer
- School of Aerospace Mechanical & Mechatronic Engineering and Australian Centre for Microscopy & Microanalysis, The University of Sydney, Sydney, NSW, 2006, Australia
| | - Jiabao Yi
- Global Innovative Center for Advanced Nanomaterials, School of Engineering, University of Newcastle, Callaghan, NSW, 2308, Australia
| |
Collapse
|
4
|
Kelly TF, Gorman BP, Ringer SP. Introduction to Atomic-Scale Tomography. Microsc Microanal 2023; 29:589-590. [PMID: 37613014 DOI: 10.1093/micmic/ozad067.284] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/25/2023]
Affiliation(s)
| | - Brian P Gorman
- Colorado School of Mines, Department of Metallurgical and Materials Engineering, Golden, CO, United States
| | - Simon P Ringer
- School of Aerospace, Mechanical & Mechatronic Engineering, University of Sydney, Sydney, Australia
| |
Collapse
|
5
|
Song T, Chen Z, Cui X, Lu S, Chen H, Wang H, Dong T, Qin B, Chan KC, Brandt M, Liao X, Ringer SP, Qian M. Strong and ductile titanium-oxygen-iron alloys by additive manufacturing. Nature 2023; 618:63-68. [PMID: 37259002 DOI: 10.1038/s41586-023-05952-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2021] [Accepted: 03/14/2023] [Indexed: 06/02/2023]
Abstract
Titanium alloys are advanced lightweight materials, indispensable for many critical applications1,2. The mainstay of the titanium industry is the α-β titanium alloys, which are formulated through alloying additions that stabilize the α and β phases3-5. Our work focuses on harnessing two of the most powerful stabilizing elements and strengtheners for α-β titanium alloys, oxygen and iron1-5, which are readily abundant. However, the embrittling effect of oxygen6,7, described colloquially as 'the kryptonite to titanium'8, and the microsegregation of iron9 have hindered their combination for the development of strong and ductile α-β titanium-oxygen-iron alloys. Here we integrate alloy design with additive manufacturing (AM) process design to demonstrate a series of titanium-oxygen-iron compositions that exhibit outstanding tensile properties. We explain the atomic-scale origins of these properties using various characterization techniques. The abundance of oxygen and iron and the process simplicity for net-shape or near-net-shape manufacturing by AM make these α-β titanium-oxygen-iron alloys attractive for a diverse range of applications. Furthermore, they offer promise for industrial-scale use of off-grade sponge titanium or sponge titanium-oxygen-iron10,11, an industrial waste product at present. The economic and environmental potential to reduce the carbon footprint of the energy-intensive sponge titanium production12 is substantial.
Collapse
Affiliation(s)
- Tingting Song
- Centre for Additive Manufacturing, School of Engineering, RMIT University, Melbourne, Victoria, Australia
| | - Zibin Chen
- School of Aerospace, Mechanical and Mechatronic Engineering, The University of Sydney, Sydney, New South Wales, Australia
- Australian Centre for Microscopy & Microanalysis, The University of Sydney, Sydney, New South Wales, Australia
- Research Institute for Advanced Manufacturing, Department of Industrial and Systems Engineering, The Hong Kong Polytechnic University, Hong Kong, China
- State Key Laboratory of Ultra-precision Machining Technology, Department of Industrial and Systems Engineering, The Hong Kong Polytechnic University, Hong Kong, China
| | - Xiangyuan Cui
- School of Aerospace, Mechanical and Mechatronic Engineering, The University of Sydney, Sydney, New South Wales, Australia
- Australian Centre for Microscopy & Microanalysis, The University of Sydney, Sydney, New South Wales, Australia
| | - Shenglu Lu
- Centre for Additive Manufacturing, School of Engineering, RMIT University, Melbourne, Victoria, Australia
| | - Hansheng Chen
- School of Aerospace, Mechanical and Mechatronic Engineering, The University of Sydney, Sydney, New South Wales, Australia
- Australian Centre for Microscopy & Microanalysis, The University of Sydney, Sydney, New South Wales, Australia
| | - Hao Wang
- School of Aerospace, Mechanical and Mechatronic Engineering, The University of Sydney, Sydney, New South Wales, Australia
- Australian Centre for Microscopy & Microanalysis, The University of Sydney, Sydney, New South Wales, Australia
| | - Tony Dong
- Hexagon Manufacturing Intelligence, Doncaster, Victoria, Australia
| | - Bailiang Qin
- Research Institute for Advanced Manufacturing, Department of Industrial and Systems Engineering, The Hong Kong Polytechnic University, Hong Kong, China
| | - Kang Cheung Chan
- Research Institute for Advanced Manufacturing, Department of Industrial and Systems Engineering, The Hong Kong Polytechnic University, Hong Kong, China
- State Key Laboratory of Ultra-precision Machining Technology, Department of Industrial and Systems Engineering, The Hong Kong Polytechnic University, Hong Kong, China
| | - Milan Brandt
- Centre for Additive Manufacturing, School of Engineering, RMIT University, Melbourne, Victoria, Australia
| | - Xiaozhou Liao
- School of Aerospace, Mechanical and Mechatronic Engineering, The University of Sydney, Sydney, New South Wales, Australia
- Australian Centre for Microscopy & Microanalysis, The University of Sydney, Sydney, New South Wales, Australia
| | - Simon P Ringer
- School of Aerospace, Mechanical and Mechatronic Engineering, The University of Sydney, Sydney, New South Wales, Australia.
- Australian Centre for Microscopy & Microanalysis, The University of Sydney, Sydney, New South Wales, Australia.
| | - Ma Qian
- Centre for Additive Manufacturing, School of Engineering, RMIT University, Melbourne, Victoria, Australia.
| |
Collapse
|
6
|
Liu H, Nomoto K, Ceguerra AV, Kruzic JJ, Cairney J, Ringer SP. EDP2PDF: a computer program for extracting a pair distribution function from an electron diffraction pattern for the structural analysis of materials. J Appl Crystallogr 2023; 56:889-902. [PMID: 37284274 PMCID: PMC10241047 DOI: 10.1107/s1600576723004053] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2022] [Accepted: 05/05/2023] [Indexed: 06/08/2023] Open
Abstract
Pair distribution function (PDF) analysis is a powerful technique to understand atomic scale structure in materials science. Unlike X-ray diffraction (XRD)-based PDF analysis, the PDF calculated from electron diffraction patterns (EDPs) using transmission electron microscopy can provide structural information from specific locations with high spatial resolution. The present work describes a new software tool for both periodic and amorphous structures that addresses several practical challenges in calculating the PDF from EDPs. The key features of this program include accurate background subtraction using a nonlinear iterative peak-clipping algorithm and automatic conversion of various types of diffraction intensity profiles into a PDF without requiring external software. The present study also evaluates the effect of background subtraction and the elliptical distortion of EDPs on PDF profiles. The EDP2PDF software is offered as a reliable tool to analyse the atomic structure of crystalline and non-crystalline materials.
Collapse
Affiliation(s)
- Hongwei Liu
- Australian Centre for Microscopy and Microanalysis, University of Sydney, Sydney, New South Wales 2006, Australia
| | - Keita Nomoto
- School of Aerospace, Mechanical and Mechatronic Engineering, University of Sydney, Sydney, New South Wales 2006, Australia
- School of Mechanical and Manufacturing Engineering, UNSW Sydney, Sydney, New South Wales 2052, Australia
| | - Anna V. Ceguerra
- Australian Centre for Microscopy and Microanalysis, University of Sydney, Sydney, New South Wales 2006, Australia
- School of Aerospace, Mechanical and Mechatronic Engineering, University of Sydney, Sydney, New South Wales 2006, Australia
| | - Jamie J. Kruzic
- School of Mechanical and Manufacturing Engineering, UNSW Sydney, Sydney, New South Wales 2052, Australia
| | - Julie Cairney
- Australian Centre for Microscopy and Microanalysis, University of Sydney, Sydney, New South Wales 2006, Australia
- School of Aerospace, Mechanical and Mechatronic Engineering, University of Sydney, Sydney, New South Wales 2006, Australia
| | - Simon P. Ringer
- Australian Centre for Microscopy and Microanalysis, University of Sydney, Sydney, New South Wales 2006, Australia
- School of Aerospace, Mechanical and Mechatronic Engineering, University of Sydney, Sydney, New South Wales 2006, Australia
| |
Collapse
|
7
|
Liang Y, Cui X, Li F, Stampfl C, Ringer SP, Yang X, Huang J, Zheng R. Origin of Enhanced Nonradiative Carrier Recombination Induced by Oxygen in Hybrid Sn Perovskite. J Phys Chem Lett 2023; 14:2950-2957. [PMID: 36930821 DOI: 10.1021/acs.jpclett.3c00423] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
Oxygen ingression has been shown to substantially decrease the carrier lifetime of Sn-based perovskites, behind which the mechanism remains yet unknown. Our first-principles calculations reveal that in prototypical MASnI3 (MA = CH3NH3), oxygen by itself is not a recombination center. Instead, it tends to form substitutional OI through combining with native I vacancies (VI) and remarkably increases the original recombination rate of VI by 2-3 orders of magnitude. This rationalizes the experimentally observed sharp decline of carrier lifetime in perovskites exposed to air. The significantly enhanced carrier recombination is due to a smaller electron capture barrier of OI, resulting from lattice strengthening and the suppressed structural relaxation upon electron capture. These insights offer a route to further improve device performance via anion engineering in broad Sn-based perovskite optoelectronics operating in ambient air. Moreover, our results highlight the important role of lattice relaxation for nonradiative carrier capture in materials in general.
Collapse
Affiliation(s)
- Yuhang Liang
- School of Chemical and Biomolecular Engineering, The University of Sydney, Sydney, NSW 2006, Australia
- School of Physics, The University of Sydney, Sydney, NSW 2006, Australia
| | - Xiangyuan Cui
- School of Aerospace, Mechanical and Mechatronic Engineering, The University of Sydney, Sydney, NSW 2006, Australia
| | - Feng Li
- School of Physics, The University of Sydney, Sydney, NSW 2006, Australia
| | - Catherine Stampfl
- School of Physics, The University of Sydney, Sydney, NSW 2006, Australia
| | - Simon P Ringer
- School of Aerospace, Mechanical and Mechatronic Engineering, The University of Sydney, Sydney, NSW 2006, Australia
| | - Xudong Yang
- State Key Laboratory of Metal Matrix Composites, Shanghai Jiao Tong University, Shanghai 200240, China
- Center of Hydrogen Science, School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
- Zhangjiang Institute for Advanced Study, Shanghai Jiao Tong University, Shanghai 201210, China
| | - Jun Huang
- School of Chemical and Biomolecular Engineering, The University of Sydney, Sydney, NSW 2006, Australia
| | - Rongkun Zheng
- School of Physics, The University of Sydney, Sydney, NSW 2006, Australia
| |
Collapse
|
8
|
Huang Q, Yang J, Chen Z, Chen Y, Cabral MJ, Luo H, Li F, Zhang S, Li Y, Xie Z, Huang H, Mai YW, Ringer SP, Liu S, Liao X. Formation of Head/Tail-to-Body Charged Domain Walls by Mechanical Stress. ACS Appl Mater Interfaces 2023; 15:2313-2318. [PMID: 36534513 DOI: 10.1021/acsami.2c14598] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Domain walls (DWs) in ferroelectric materials are interfaces that separate domains with different polarizations. Charged domain walls (CDWs) and neutral domain walls are commonly classified depending on the charge state at the DWs. CDWs are particularly attractive as they are configurable elements, which can enhance field susceptibility and enable functionalities such as conductance control. However, it is difficult to achieve CDWs in practice. Here, we demonstrate that applying mechanical stress is a robust and reproducible approach to generate CDWs. By mechanical compression, CDWs with a head/tail-to-body configuration were introduced in ultrathin BaTiO3, which was revealed by in-situ transmission electron microscopy. Finite element analysis shows strong strain fluctuation in ultrathin BaTiO3 under compressive mechanical stress. Molecular dynamics simulations suggest that the strain fluctuation is a critical factor in forming CDWs. This study provides insight into ferroelectric DWs and opens a pathway to creating CDWs in ferroelectric materials.
Collapse
Affiliation(s)
- Qianwei Huang
- School of Aerospace, Mechanical and Mechatronic Engineering, The University of Sydney, Sydney, New South Wales2006, Australia
| | - Jiyuan Yang
- Key Laboratory for Quantum Materials of Zhejiang Province, Department of Physics, School of Science, Westlake University, Hangzhou, Zhejiang310030, China
- Institute of Natural Sciences, Westlake Institute for Advanced Study, Hangzhou, Zhejiang310024, China
| | - Zibin Chen
- Department of Industrial and Systems Engineering, The Hong Kong Polytechnic University, Hong Kong, China
| | - Yujie Chen
- School of Mechanical Engineering, The University of Adelaide, Adelaide, South Australia5005, Australia
| | - Matthew J Cabral
- School of Aerospace, Mechanical and Mechatronic Engineering, The University of Sydney, Sydney, New South Wales2006, Australia
| | - Haosu Luo
- Key Laboratory of Inorganic Functional Materials and Devices, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai200050, China
| | - Fei Li
- Electronic Materials Research Laboratory, Key Laboratory of the Ministry of Education, Xi'an Jiaotong University, Xi'an710049, China
| | - Shujun Zhang
- Institute for Superconducting and Electronic Materials, Australian Institute of Innovative Materials, University of Wollongong, Wollongong, New South Wales2522, Australia
| | - Yulan Li
- Pacific Northwest National Laboratory, 902 Battelle Boulevard, Richland, Washington99352, United States
| | - Zonghan Xie
- School of Mechanical Engineering, The University of Adelaide, Adelaide, South Australia5005, Australia
| | - Houbing Huang
- School of Materials Science and Engineering, Beijing Institute of Technology, Beijing100081, China
| | - Yiu-Wing Mai
- School of Aerospace, Mechanical and Mechatronic Engineering, The University of Sydney, Sydney, New South Wales2006, Australia
| | - Simon P Ringer
- School of Aerospace, Mechanical and Mechatronic Engineering, The University of Sydney, Sydney, New South Wales2006, Australia
| | - Shi Liu
- Key Laboratory for Quantum Materials of Zhejiang Province, Department of Physics, School of Science, Westlake University, Hangzhou, Zhejiang310030, China
- Institute of Natural Sciences, Westlake Institute for Advanced Study, Hangzhou, Zhejiang310024, China
| | - Xiaozhou Liao
- School of Aerospace, Mechanical and Mechatronic Engineering, The University of Sydney, Sydney, New South Wales2006, Australia
| |
Collapse
|
9
|
Day AC, Breen AJ, Reinhard DA, Kelly TF, Ringer SP. Exploration of atom probe tomography at sub-10 K. Ultramicroscopy 2022; 241:113595. [DOI: 10.1016/j.ultramic.2022.113595] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2022] [Revised: 07/15/2022] [Accepted: 07/21/2022] [Indexed: 10/31/2022]
|
10
|
Liang Y, Cui X, Li F, Stampfl C, Ringer SP, Huang J, Zheng R. Minimizing and Controlling Hydrogen for Highly Efficient Formamidinium Lead Triiodide Solar Cells. J Am Chem Soc 2022; 144:6770-6778. [PMID: 35385287 DOI: 10.1021/jacs.2c00038] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Formamidinium lead triiodide (FAPbI3) currently holds the record conversion efficiency in the single-junction perovskite solar cell. Iodine management is known to be essential to suppress defect-induced nonradiative losses in FAPbI3 active layers. However, the origin of nonradiative losses and the underlying mechanism of suppressing such losses by iodine-concentration management remain unknown. Here, through first-principles simulation, we demonstrate that native point defects are not responsible for the nonradiative losses in FAPbI3. Instead, hydrogen ions, which can be abundant under both iodine-rich and iodine-poor conditions in FAPbI3, act as efficient nonradiative recombination centers and are proposed to be responsible for the suppressed power conversion efficiency. Moreover, iodine-moderate synthesis conditions can favor the formation of electrically inactive molecular hydrogen, which can dramatically suppress the detrimental hydrogen ions. This work identifies the dominant nonradiative recombination centers in the widely used FAPbI3 layers and rationalizes how the prevailing iodine management reduces the nonradiative losses. Minimizing the unintentional hydrogen incorporation in the perovskite is critical for achieving high device performance.
Collapse
Affiliation(s)
- Yuhang Liang
- School of Chemical and Biomolecular Engineering, The University of Sydney, Sydney, New South Wales 2006, Australia.,School of Physics, The University of Sydney, Sydney, New South Wales 2006, Australia
| | - Xiangyuan Cui
- School of Aerospace, Mechanical and Mechatronic Engineering, The University of Sydney, Sydney, New South Wales 2006, Australia
| | - Feng Li
- School of Physics, The University of Sydney, Sydney, New South Wales 2006, Australia
| | - Catherine Stampfl
- School of Physics, The University of Sydney, Sydney, New South Wales 2006, Australia
| | - Simon P Ringer
- School of Aerospace, Mechanical and Mechatronic Engineering, The University of Sydney, Sydney, New South Wales 2006, Australia
| | - Jun Huang
- School of Chemical and Biomolecular Engineering, The University of Sydney, Sydney, New South Wales 2006, Australia
| | - Rongkun Zheng
- School of Physics, The University of Sydney, Sydney, New South Wales 2006, Australia
| |
Collapse
|
11
|
Qu J, Yang W, Wu T, Ren W, Huang J, Yu H, Zhao C, Griffith MJ, Zheng R, Ringer SP, Cairney JM. Atom probe specimen preparation methods for nanoparticles. Ultramicroscopy 2022; 233:113420. [PMID: 34775241 DOI: 10.1016/j.ultramic.2021.113420] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Revised: 10/26/2021] [Accepted: 10/31/2021] [Indexed: 11/17/2022]
Abstract
Revealing the position of materials with chemical selectivity at atomic scale within functional nanoparticles is essential to understand and control their performance and cutting-edge atom probe tomography is a powerful tool to undertake this task. In this paper, we demonstrate three effective methods to prepare the needle-shaped specimens required for atom probe tomography measurements from nanoparticles of different sizes and provide examples of how atom probe can be used to provide data that is critical to their functionality. Samples measured include lithium-ion batteries (LIBs) cathode nanoparticles (300 - 500 nm), nickel-doped silicon dioxide (Ni@SiO2) catalytic nanoparticles (100 - 200 nm) and tin-doped copper (Sn@Cu) catalytic nanoparticles (<100 nm). The methods presented can be used to address the ongoing challenge of specimen preparation from particle samples for atom probe measurement, and they provide high quality data. These methods will broaden the application of atom probe tomography and will provide alternative option for researchers to assess the performance/structure of their functional nanomaterials.
Collapse
Affiliation(s)
- Jiangtao Qu
- Australian Centre for Microscopy & Microanalysis
| | - Wenjie Yang
- School of Chemical and Biomolecular Engineering
| | - Tianhao Wu
- Key Laboratory of Advanced Functional Materials, Beijing University of Technology, Beijing 100124 China
| | - Wenhao Ren
- School of Chemistry, University of New South Wales, 2052 NSW, Australia
| | - Jun Huang
- School of Chemical and Biomolecular Engineering
| | - Haijun Yu
- Key Laboratory of Advanced Functional Materials, Beijing University of Technology, Beijing 100124 China
| | - Chuan Zhao
- School of Chemistry, University of New South Wales, 2052 NSW, Australia
| | | | - Rongkun Zheng
- Australian Centre for Microscopy & Microanalysis; the School of Physics
| | - Simon P Ringer
- Australian Centre for Microscopy & Microanalysis; School of Aerospace, Mechanical and Mechatronic Engineering, the University of Sydney, 2006, Australia
| | - Julie M Cairney
- Australian Centre for Microscopy & Microanalysis; School of Aerospace, Mechanical and Mechatronic Engineering, the University of Sydney, 2006, Australia.
| |
Collapse
|
12
|
Liu Y, Cui X, Niu R, Zhang S, Liao X, Moss SD, Finkel P, Garbrecht M, Ringer SP, Cairney JM. Giant room temperature compression and bending in ferroelectric oxide pillars. Nat Commun 2022; 13:335. [PMID: 35039489 PMCID: PMC8764079 DOI: 10.1038/s41467-022-27952-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2021] [Accepted: 10/10/2021] [Indexed: 11/16/2022] Open
Abstract
Plastic deformation in ceramic materials is normally only observed in nanometre-sized samples. However, we have observed high levels of plasticity (>50% plastic strain) and excellent elasticity (6% elastic strain) in perovskite oxide Pb(In1/2Nb1/2)O3-Pb(Mg1/3Nb2/3)O3-PbTiO3, under compression along <100>pc pillars up to 2.1 μm in diameter. The extent of this deformation is much higher than has previously been reported for ceramic materials, and the sample size at which plasticity is observed is almost an order of magnitude larger. Bending tests also revealed over 8% flexural strain. Plastic deformation occurred by slip along {110} <1[Formula: see text]0 > . Calculations indicate that the resulting strain gradients will give rise to giant flexoelectric polarization. First principles models predict that a high concentration of oxygen vacancies weaken the covalent/ionic bonds, giving rise to the unexpected plasticity. Mechanical testing on oxygen vacancies-rich Mn-doped Pb(In1/2Nb1/2)O3-Pb(Mg1/3Nb2/3)O3-PbTiO3 confirmed this prediction. These findings will facilitate the design of plastic ceramic materials and the development of flexoelectric-based nano-electromechanical systems.
Collapse
Affiliation(s)
- Ying Liu
- School of Aerospace, Mechanical & Mechatronic Engineering, The University of Sydney, Sydney, NSW, 2006, Australia
- Australian Centre for Microscopy and Microanalysis, The University of Sydney, Sydney, NSW, 2006, Australia
| | - Xiangyuan Cui
- School of Aerospace, Mechanical & Mechatronic Engineering, The University of Sydney, Sydney, NSW, 2006, Australia
- Australian Centre for Microscopy and Microanalysis, The University of Sydney, Sydney, NSW, 2006, Australia
| | - Ranming Niu
- School of Aerospace, Mechanical & Mechatronic Engineering, The University of Sydney, Sydney, NSW, 2006, Australia
| | - Shujun Zhang
- ISEM, Australian Institute of Innovative Materials, University of Wollongong, Wollongong, NSW, 2500, Australia
| | - Xiaozhou Liao
- School of Aerospace, Mechanical & Mechatronic Engineering, The University of Sydney, Sydney, NSW, 2006, Australia
| | - Scott D Moss
- Aerospace Division, Defence Science and Technology Group, Melbourne, VIC, 3207, Australia
| | - Peter Finkel
- US Naval Research Laboratory, Washington DC, 20375, USA
| | - Magnus Garbrecht
- Australian Centre for Microscopy and Microanalysis, The University of Sydney, Sydney, NSW, 2006, Australia
| | - Simon P Ringer
- School of Aerospace, Mechanical & Mechatronic Engineering, The University of Sydney, Sydney, NSW, 2006, Australia
| | - Julie M Cairney
- School of Aerospace, Mechanical & Mechatronic Engineering, The University of Sydney, Sydney, NSW, 2006, Australia.
- Australian Centre for Microscopy and Microanalysis, The University of Sydney, Sydney, NSW, 2006, Australia.
| |
Collapse
|
13
|
Nomoto K, Cui XY, Breen A, Ceguerra AV, Perez-Wurfl I, Conibeer G, Ringer SP. Effects of thermal annealing on the distribution of boron and phosphorus in p-i-n structured silicon nanocrystals embedded in silicon dioxide. Nanotechnology 2021; 33:075709. [PMID: 34763327 DOI: 10.1088/1361-6528/ac38e6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/23/2021] [Accepted: 11/11/2021] [Indexed: 06/13/2023]
Abstract
Thermal annealing temperature and time dictate the microstructure of semiconductor materials such as silicon nanocrystals (Si NCs). Herein, atom probe tomography (APT) and density functional theory (DFT) calculations are used to understand the thermal annealing temperature effects on Si NCs grown in a SiO2matrix and the distribution behaviour of boron (B) and phosphorus (P) dopant atoms. The APT results demonstrate that raising the annealing temperature promotes growth and increased P concentration of the Si NCs. The data also shows that the thermal annealing does not promote the incorporation of B atoms into Si NCs. Instead, B atoms tend to locate at the interface between the Si NCs and SiO2matrix. The DFT calculations support the APT data and reveal that oxygen vacancies regulate Si NC growth and dopant distribution. This study provides the detailed microstructure of p-type, intrinsic, and n-type Si NCs with changing annealing temperature and highlights how B and P dopants preferentially locate with respect to the Si NCs embedded in the SiO2matrix with the aid of oxygen vacancies. These findings will be useful towards future optoelectronic applications.
Collapse
Affiliation(s)
- Keita Nomoto
- The University of Sydney, Australian Centre for Microscopy & Microanalysis and School of Aerospace Mechanical and Mechatronic Engineering, 2006 Sydney, Australia
| | - Xiang-Yuan Cui
- The University of Sydney, Australian Centre for Microscopy & Microanalysis and School of Aerospace Mechanical and Mechatronic Engineering, 2006 Sydney, Australia
| | - Andrew Breen
- The University of Sydney, Australian Centre for Microscopy & Microanalysis and School of Aerospace Mechanical and Mechatronic Engineering, 2006 Sydney, Australia
| | - Anna V Ceguerra
- The University of Sydney, Australian Centre for Microscopy & Microanalysis and School of Aerospace Mechanical and Mechatronic Engineering, 2006 Sydney, Australia
| | - Ivan Perez-Wurfl
- School of Photovoltaic and Renewable Energy Engineering, The University of New South Wales, 2052 Kensington, Australia
| | - Gavin Conibeer
- School of Photovoltaic and Renewable Energy Engineering, The University of New South Wales, 2052 Kensington, Australia
| | - Simon P Ringer
- The University of Sydney, Australian Centre for Microscopy & Microanalysis and School of Aerospace Mechanical and Mechatronic Engineering, 2006 Sydney, Australia
| |
Collapse
|
14
|
Liang Y, Cui X, Li F, Stampfl C, Huang J, Ringer SP, Zheng R. Hydrogen-Anion-Induced Carrier Recombination in MAPbI 3 Perovskite Solar Cells. J Phys Chem Lett 2021; 12:10677-10683. [PMID: 34709819 DOI: 10.1021/acs.jpclett.1c03061] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Identification and passivation of defect-induced electron-hole recombination centers are currently crucial for improving the efficiency of hybrid perovskite solar cells. Besides general intrinsic defects, experimental reports have indicated that hydrogen interstitials are also abundant in hybrid perovskite layers; however, few reports have evaluated the effect of such defects on the charge carrier recombination and device efficiencies. Here, we reveal that under I-poor synthesis conditions, the negatively charged monatomic hydrogen interstitial, Hi-, will form in the prototypical CH3NH3PbI3 perovskite layer, acting as a detrimental deep-level defect, which leads to efficient electron-hole recombination and lowers the cell performance. We further rationalize that Br doping can mitigate the large atomic displacement caused by the presence of Hi- and hence suppress the formation of the deep localized state. The results advance the knowledge of the deep-level defects in hybrid perovskites and provide useful information for enhancing solar cell performance by defect engineering.
Collapse
Affiliation(s)
- Yuhang Liang
- School of Physics, The University of Sydney, Sydney, NSW 2006, Australia
| | - Xiangyuan Cui
- School of Aerospace, Mechanical and Mechatronic Engineering, The University of Sydney, Sydney, NSW 2006, Australia
| | - Feng Li
- School of Physics, The University of Sydney, Sydney, NSW 2006, Australia
| | - Catherine Stampfl
- School of Physics, The University of Sydney, Sydney, NSW 2006, Australia
| | - Jun Huang
- School of Chemical and Biomolecular Engineering, The University of Sydney, Sydney, NSW 2006, Australia
| | - Simon P Ringer
- School of Aerospace, Mechanical and Mechatronic Engineering, The University of Sydney, Sydney, NSW 2006, Australia
| | - Rongkun Zheng
- School of Physics, The University of Sydney, Sydney, NSW 2006, Australia
| |
Collapse
|
15
|
Huang Q, Chen Z, Cabral MJ, Luo H, Liu H, Zhang S, Li Y, Mai YW, Ringer SP, Liao X. Manipulating ferroelectric behaviors via electron-beam induced crystalline defects. Nanoscale 2021; 13:14330-14336. [PMID: 34477716 DOI: 10.1039/d1nr04300e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Ferroelectric nanoplates are attractive for applications in nanoelectronic devices. Defect engineering has been an effective way to control and manipulate ferroelectric properties in nanoscale devices. Defects can act as pinning centers for ferroelectric domain wall motion, altering the switching properties and domain dynamics of ferroelectrics. However, there is a lack of detailed investigation on the interactions between defects and domain walls in ferroelectric nanoplates due to the limitation of previous characterization techniques, which impedes the development of defect engineering in ferroelectric nanodevices. In this study, we applied in situ biasing transmission electron microscopy to explore how dislocation loops, which were judiciously introduced into barium titanate nanoplates via electron beam irradiation, affect the motion of ferroelectric domain walls. The results show that the motion was dramatically suppressed by these localized defects, because of the local strain fields induced by the defects. The pinning effect can be further enhanced by multiple domain walls embedded with defect arrays. These results indicate the possibility of manipulating domain switching in ferroelectric nanoplates via the electron beam.
Collapse
Affiliation(s)
- Qianwei Huang
- School of Aerospace, Mechanical and Mechatronic Engineering, The University of Sydney, Darlington, NSW 2008, Australia.
| | | | | | | | | | | | | | | | | | | |
Collapse
|
16
|
Yang T, Jin C, Qu J, Darvish AA, Sabatini R, Zhang X, Chen H, Ringer SP, Lakhwani G, Li F, Cairney J, Liu X, Zheng R. Solution Epitaxy of Halide Perovskite Thin Single Crystals for Stable Transistors. ACS Appl Mater Interfaces 2021; 13:37840-37848. [PMID: 34314169 DOI: 10.1021/acsami.1c08800] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Halide perovskites hold promise for energy and optoelectronic applications due to their fascinating photophysical properties and facile processing. Among various forms, epitaxial thin single crystals (TSCs) are highly desirable due to their high crystallinity, reduced defects, and easy epitaxial integration with other materials. However, a cost-effective method for obtaining TSCs with perfect epitaxial features remains elusive. Here, we demonstrate a direct epitaxial growth of high-quality all-inorganic perovskite CsPbBr3 TSCs on various substrates through a facile solution process under near-ambient conditions. Structural characterizations reveal a high-quality epitaxy between the obtained perovskite TSCs and substrates, thus leading to efficiently reduced defects. The resultant TSCs display a low trap density (∼1011 cm-3) and a long carrier lifetime (∼10.16 ns). Top-gate/top-contact transistors based on these TSCs exhibit high on/off ratios of over 105, an optimal hole mobility of 3.9 cm2 V-1 s-1, almost hysteresis-free operation, and high stability at room temperature. Such a facile approach for the high-yield production of perovskite epitaxial TSCs will enable a broad range of high-performance electronic applications.
Collapse
Affiliation(s)
- Tiebin Yang
- School of Physics, Australian Centre for Microscopy and Microanalysis, Sydney Nano Institute, The University of Sydney, Sydney, New South Wales 2006, Australia
| | - Chao Jin
- Tianjin Key Laboratory of Low Dimensional Materials Physics and Processing Technology, School of Science, Tianjin University, Tianjin 300350, China
| | - Jiangtao Qu
- School of Aerospace, Mechanical and Mechatronic Engineering, Australian Centre for Microscopy and Microanalysis, The University of Sydney, Sydney, New South Wales 2006, Australia
| | - Amir Asadpoor Darvish
- ARC Centre of Excellence in Exciton Science, School of Chemistry, The University of Sydney, Sydney, New South Wales 2006, Australia
| | - Randy Sabatini
- ARC Centre of Excellence in Exciton Science, School of Chemistry, The University of Sydney, Sydney, New South Wales 2006, Australia
| | - Xingmo Zhang
- School of Physics, Australian Centre for Microscopy and Microanalysis, Sydney Nano Institute, The University of Sydney, Sydney, New South Wales 2006, Australia
| | - Hansheng Chen
- School of Aerospace, Mechanical and Mechatronic Engineering, Australian Centre for Microscopy and Microanalysis, The University of Sydney, Sydney, New South Wales 2006, Australia
| | - Simon P Ringer
- School of Aerospace, Mechanical and Mechatronic Engineering, Australian Centre for Microscopy and Microanalysis, The University of Sydney, Sydney, New South Wales 2006, Australia
| | - Girish Lakhwani
- ARC Centre of Excellence in Exciton Science, School of Chemistry, The University of Sydney, Sydney, New South Wales 2006, Australia
| | - Feng Li
- School of Physics, Australian Centre for Microscopy and Microanalysis, Sydney Nano Institute, The University of Sydney, Sydney, New South Wales 2006, Australia
| | - Julie Cairney
- School of Aerospace, Mechanical and Mechatronic Engineering, Australian Centre for Microscopy and Microanalysis, The University of Sydney, Sydney, New South Wales 2006, Australia
| | - Xiaogang Liu
- Department of Chemistry, National University of Singapore, Singapore 117543, Singapore
| | - Rongkun Zheng
- School of Physics, Australian Centre for Microscopy and Microanalysis, Sydney Nano Institute, The University of Sydney, Sydney, New South Wales 2006, Australia
| |
Collapse
|
17
|
Huang Q, Chen Z, Cabral MJ, Wang F, Zhang S, Li F, Li Y, Ringer SP, Luo H, Mai YW, Liao X. Direct observation of nanoscale dynamics of ferroelectric degradation. Nat Commun 2021; 12:2095. [PMID: 33828086 PMCID: PMC8027400 DOI: 10.1038/s41467-021-22355-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2020] [Accepted: 03/11/2021] [Indexed: 02/01/2023] Open
Abstract
Failure of polarization reversal, i.e., ferroelectric degradation, induced by cyclic electric loadings in ferroelectric materials, has been a long-standing challenge that negatively impacts the application of ferroelectrics in devices where reliability is critical. It is generally believed that space charges or injected charges dominate the ferroelectric degradation. However, the physics behind the phenomenon remains unclear. Here, using in-situ biasing transmission electron microscopy, we discover change of charge distribution in thin ferroelectrics during cyclic electric loadings. Charge accumulation at domain walls is the main reason of the formation of c domains, which are less responsive to the applied electric field. The rapid growth of the frozen c domains leads to the ferroelectric degradation. This finding gives insights into the nature of ferroelectric degradation in nanodevices, and reveals the role of the injected charges in polarization reversal.
Collapse
Affiliation(s)
- Qianwei Huang
- grid.1013.30000 0004 1936 834XSchool of Aerospace, Mechanical and Mechatronic Engineering, The University of Sydney, Sydney, NSW Australia
| | - Zibin Chen
- grid.1013.30000 0004 1936 834XSchool of Aerospace, Mechanical and Mechatronic Engineering, The University of Sydney, Sydney, NSW Australia
| | - Matthew J. Cabral
- grid.1013.30000 0004 1936 834XSchool of Aerospace, Mechanical and Mechatronic Engineering, The University of Sydney, Sydney, NSW Australia
| | - Feifei Wang
- grid.412531.00000 0001 0701 1077Key Laboratory of Optoelectronic Material and Device, Department of Physics, Shanghai Normal University, Shanghai, China
| | - Shujun Zhang
- grid.1007.60000 0004 0486 528XInstitute for Superconducting and Electronic Materials, Australian Institute of Innovative Materials, University of Wollongong, Wollongong, NSW Australia
| | - Fei Li
- grid.43169.390000 0001 0599 1243Electronic Materials Research Laboratory, Key Laboratory of the Ministry of Education, Xi’an Jiaotong University, Xi’an, China
| | - Yulan Li
- grid.451303.00000 0001 2218 3491Pacific Northwest National Laboratory, Richland, WA USA
| | - Simon P. Ringer
- grid.1013.30000 0004 1936 834XSchool of Aerospace, Mechanical and Mechatronic Engineering, The University of Sydney, Sydney, NSW Australia
| | - Haosu Luo
- grid.9227.e0000000119573309Key Laboratory of Inorganic Functional Materials and Devices, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai, China
| | - Yiu-Wing Mai
- grid.1013.30000 0004 1936 834XSchool of Aerospace, Mechanical and Mechatronic Engineering, The University of Sydney, Sydney, NSW Australia
| | - Xiaozhou Liao
- grid.1013.30000 0004 1936 834XSchool of Aerospace, Mechanical and Mechatronic Engineering, The University of Sydney, Sydney, NSW Australia
| |
Collapse
|
18
|
Day AC, Breen AJ, Ringer SP. A Crystallography-Mediated Reconstruction (CMR) Approach for Atom Probe Tomography: Solution for a Singleton Pole. Ultramicroscopy 2021; 224:113262. [PMID: 33798817 DOI: 10.1016/j.ultramic.2021.113262] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2020] [Revised: 01/27/2021] [Accepted: 03/12/2021] [Indexed: 11/19/2022]
Abstract
Spatially accurate atom probe tomography reconstructions are vitally important when quantitative spatial measurements such as distances, volumes and morphologies etc. of nanostructural features are required information for the researcher. It is well known that the crystallographic information contained within the atom probe data of crystalline materials can be used to calibrate the tomographic reconstruction. Specifically, the crystallographic information projected into the field evaporation images is used. This offers a powerful and accurate enhancement of the atom probe technique. However, this is often difficult to do in practice. In previously reported approaches, it was necessary to index at least two poles to compute the image compression factor 'ξ' and observe crystallographic planes in at least one of the pole regions to obtain a measure of the field factor 'kf' while also manually accounting for a change in reconstruction parameters throughout the dataset. Not only is this error-prone and time consuming, it does not work for materials that exhibit limited crystallographic information in their field evaporation image. Here, we extend the applicability of the crystallographic calibration of atom probe data by proposing a reconstruction methodology where only one pole with observable lattice planes is required in the projected detector image. Our proposal also accounts for dynamic variations in the reconstruction parameters throughout the 3D dataset. The method is simpler and significantly faster to implement and is applicable to more atom probe situations than previously approaches. Our single-pole crystallography mediated reconstruction (SP-CMR) utilizes the Hawkes-Kasper projection model (equivalent to the equidistant-azimuthal projection model) and the direct fourier (DF) fit algorithm to determine the precise reconstruction parameters required to produce flat atomic planes. It is applied to experimental Al and highly Sb-doped Si data. The discrepancies between the spatial dimensions of the SP-CMR reconstructions compared to uncalibrated reconstructions are visually apparent. Consistent plane spacings and angles between crystallographic directions matching the theoretically known values for each crystal structure are demonstrated.
Collapse
Affiliation(s)
- Alec C Day
- The University of Sydney; Australian Centre for Microscopy & Microanalysis, and School of Aerospace, Mechanical and Mechatronic Engineering. Sydney, NSW 2006, Australia.
| | - Andrew J Breen
- The University of Sydney; Australian Centre for Microscopy & Microanalysis, and School of Aerospace, Mechanical and Mechatronic Engineering. Sydney, NSW 2006, Australia
| | - Simon P Ringer
- The University of Sydney; Australian Centre for Microscopy & Microanalysis, and School of Aerospace, Mechanical and Mechatronic Engineering. Sydney, NSW 2006, Australia.
| |
Collapse
|
19
|
Abstract
Accurate simulation of semiconductor nanowires (NWs) under strain is challenging, especially for bent NWs. Here, we propose a simple yet efficient unit-cell model to simulate strain-mediated bandgap modulation in both straight and bent NWs. This is with consideration that uniaxlly bent NWs experience continuous compressive and tensile strains through their cross-sections. A systematic investigation of a series of III-V and II-VI semiconductors NWs in both wurtzite and zinc blende polytypes is performed using hybrid density functional theory methods. The results reveal three common trend in bandgap evolution upon application of strain. Existing experimental measurements corroborate with our predictions concerning bandgap evolution as well as direct-indirect bandgap transitions upon strain. By examining the variation of previous theoretical studies, our result further highlights the significance of geometrical relaxtion in NW simulation. This simplified model is expected to be applicable to investigations of the electronic, optoelectronic, and sensorial properties of all semiconductor NWs.
Collapse
Affiliation(s)
- Bryan Lim
- The University of Sydney, School of Aeronautical, Mechanical and Mechatronic Engineering and Australian Centre for Microscopy and Microanalysis, Sydney, New South Wales 2006, Australia.
| | - Xiang Yuan Cui
- The University of Sydney, School of Aeronautical, Mechanical and Mechatronic Engineering and Australian Centre for Microscopy and Microanalysis, Sydney, New South Wales 2006, Australia.
| | - Simon P Ringer
- The University of Sydney, School of Aeronautical, Mechanical and Mechatronic Engineering and Australian Centre for Microscopy and Microanalysis, Sydney, New South Wales 2006, Australia.
| |
Collapse
|
20
|
Ren W, Tan X, Qu J, Li S, Li J, Liu X, Ringer SP, Cairney JM, Wang K, Smith SC, Zhao C. Isolated copper-tin atomic interfaces tuning electrocatalytic CO 2 conversion. Nat Commun 2021; 12:1449. [PMID: 33664236 PMCID: PMC7933149 DOI: 10.1038/s41467-021-21750-y] [Citation(s) in RCA: 48] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Accepted: 02/10/2021] [Indexed: 02/06/2023] Open
Abstract
Direct experimental observations of the interface structure can provide vital insights into heterogeneous catalysis. Examples of interface design based on single atom and surface science are, however, extremely rare. Here, we report Cu-Sn single-atom surface alloys, where isolated Sn sites with high surface densities (up to 8%) are anchored on the Cu host, for efficient electrocatalytic CO2 reduction. The unique geometric and electronic structure of the Cu-Sn surface alloys (Cu97Sn3 and Cu99Sn1) enables distinct catalytic selectivity from pure Cu100 and Cu70Sn30 bulk alloy. The Cu97Sn3 catalyst achieves a CO Faradaic efficiency of 98% at a tiny overpotential of 30 mV in an alkaline flow cell, where a high CO current density of 100 mA cm-2 is obtained at an overpotential of 340 mV. Density functional theory simulation reveals that it is not only the elemental composition that dictates the electrocatalytic reactivity of Cu-Sn alloys; the local coordination environment of atomically dispersed, isolated Cu-Sn bonding plays the most critical role.
Collapse
Affiliation(s)
- Wenhao Ren
- School of Chemistry, University of New South Wales, Sydney, NSW, Australia
| | - Xin Tan
- Integrated Materials Design Laboratory, Department of Applied Mathematics, Research School of Physics, The Australian National University Canberra, Canberra, ACT, Australia
| | - Jiangtao Qu
- Aerospace, Mechanical and Mechatronic Engineering, The University of Sydney, Sydney, NSW, Australia
- Australian Centre for Microscopy and Microanalysis, The University of Sydney, Sydney, NSW, Australia
| | - Sesi Li
- School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, Shanghai, China
| | - Jiantao Li
- State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan, China
| | - Xin Liu
- School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, Shanghai, China
| | - Simon P Ringer
- Aerospace, Mechanical and Mechatronic Engineering, The University of Sydney, Sydney, NSW, Australia
| | - Julie M Cairney
- Aerospace, Mechanical and Mechatronic Engineering, The University of Sydney, Sydney, NSW, Australia
- Australian Centre for Microscopy and Microanalysis, The University of Sydney, Sydney, NSW, Australia
| | - Kaixue Wang
- School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, Shanghai, China
| | - Sean C Smith
- Integrated Materials Design Laboratory, Department of Applied Mathematics, Research School of Physics, The Australian National University Canberra, Canberra, ACT, Australia
| | - Chuan Zhao
- School of Chemistry, University of New South Wales, Sydney, NSW, Australia.
| |
Collapse
|
21
|
Wang H, Chen D, An X, Zhang Y, Sun S, Tian Y, Zhang Z, Wang A, Liu J, Song M, Ringer SP, Zhu T, Liao X. Deformation-induced crystalline-to-amorphous phase transformation in a CrMnFeCoNi high-entropy alloy. Sci Adv 2021; 7:7/14/eabe3105. [PMID: 33789894 PMCID: PMC8011962 DOI: 10.1126/sciadv.abe3105] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/13/2020] [Accepted: 02/11/2021] [Indexed: 05/23/2023]
Abstract
The Cantor high-entropy alloy (HEA) of CrMnFeCoNi is a solid solution with a face-centered cubic structure. While plastic deformation in this alloy is usually dominated by dislocation slip and deformation twinning, our in situ straining transmission electron microscopy (TEM) experiments reveal a crystalline-to-amorphous phase transformation in an ultrafine-grained Cantor alloy. We find that the crack-tip structural evolution involves a sequence of formation of the crystalline, lamellar, spotted, and amorphous patterns, which represent different proportions and organizations of the crystalline and amorphous phases. Such solid-state amorphization stems from both the high lattice friction and high grain boundary resistance to dislocation glide in ultrafine-grained microstructures. The resulting increase of crack-tip dislocation densities promotes the buildup of high stresses for triggering the crystalline-to-amorphous transformation. We also observe the formation of amorphous nanobridges in the crack wake. These amorphization processes dissipate strain energies, thereby providing effective toughening mechanisms for HEAs.
Collapse
Affiliation(s)
- Hao Wang
- School of Aerospace, Mechanical and Mechatronic Engineering, The University of Sydney, Sydney, NSW 2006, Australia
| | - Dengke Chen
- Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, GA, 30332, USA
| | - Xianghai An
- School of Aerospace, Mechanical and Mechatronic Engineering, The University of Sydney, Sydney, NSW 2006, Australia.
| | - Yin Zhang
- Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, GA, 30332, USA
| | - Shijie Sun
- Laboratory of Fatigue and Fracture for Materials, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China
| | - Yanzhong Tian
- Key Laboratory for Anisotropy and Texture of Materials (Ministry of Education), School of Materials Science and Engineering, Northeastern University, Shenyang 110819, China
- Research Center for Metal Wires, Northeastern University, Shenyang 110819, China
| | - Zhefeng Zhang
- Laboratory of Fatigue and Fracture for Materials, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China
| | - Anguo Wang
- School of Aerospace, Mechanical and Mechatronic Engineering, The University of Sydney, Sydney, NSW 2006, Australia
| | - Jinqiao Liu
- School of Aerospace, Mechanical and Mechatronic Engineering, The University of Sydney, Sydney, NSW 2006, Australia
| | - Min Song
- State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083, China
| | - Simon P Ringer
- School of Aerospace, Mechanical and Mechatronic Engineering, The University of Sydney, Sydney, NSW 2006, Australia
| | - Ting Zhu
- Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, GA, 30332, USA.
| | - Xiaozhou Liao
- School of Aerospace, Mechanical and Mechatronic Engineering, The University of Sydney, Sydney, NSW 2006, Australia.
| |
Collapse
|
22
|
Gao X, Cheng Z, Chen Z, Liu Y, Meng X, Zhang X, Wang J, Guo Q, Li B, Sun H, Gu Q, Hao H, Shen Q, Wu J, Liao X, Ringer SP, Liu H, Zhang L, Chen W, Li F, Zhang S. The mechanism for the enhanced piezoelectricity in multi-elements doped (K,Na)NbO 3 ceramics. Nat Commun 2021; 12:881. [PMID: 33564001 PMCID: PMC7873261 DOI: 10.1038/s41467-021-21202-7] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2020] [Accepted: 01/18/2021] [Indexed: 01/30/2023] Open
Abstract
(K,Na)NbO3 based ceramics are considered to be one of the most promising lead-free ferroelectrics replacing Pb(Zr,Ti)O3. Despite extensive studies over the last two decades, the mechanism for the enhanced piezoelectricity in multi-elements doped (K,Na)NbO3 ceramics has not been fully understood. Here, we combine temperature-dependent synchrotron x-ray diffraction and property measurements, atomic-scale scanning transmission electron microscopy, and first-principle and phase-field calculations to establish the dopant-structure-property relationship for multi-elements doped (K,Na)NbO3 ceramics. Our results indicate that the dopants induced tetragonal phase and the accompanying high-density nanoscale heterostructures with low-angle polar vectors are responsible for the high dielectric and piezoelectric properties. This work explains the mechanism of the high piezoelectricity recently achieved in (K,Na)NbO3 ceramics and provides guidance for the design of high-performance ferroelectric ceramics, which is expected to benefit numerous functional materials.
Collapse
Affiliation(s)
- Xiaoyi Gao
- State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, School of Materials Science and Engineering, Wuhan University of Technology, Wuhan, China
- Institute for Superconducting and Electronic Materials, Australian Institute for Innovative Materials, University of Wollongong, Wollongong, NSW, Australia
- State Key Laboratory of Silicate Materials for Architectures, Center for Smart Materials and Device Integration, Wuhan University of Technology, Wuhan, China
| | - Zhenxiang Cheng
- Institute for Superconducting and Electronic Materials, Australian Institute for Innovative Materials, University of Wollongong, Wollongong, NSW, Australia
| | - Zibin Chen
- School of Aerospace, Mechanical and Mechatronic Engineering, The University of Sydney, Sydney, NSW, Australia
| | - Yao Liu
- Electronic Materials Research Laboratory, Key Laboratory of the Ministry of Education and International Center for Dielectric Research, Xi'an Jiaotong University, Xi'an, China
| | - Xiangyu Meng
- State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, School of Materials Science and Engineering, Wuhan University of Technology, Wuhan, China
| | - Xu Zhang
- State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, School of Materials Science and Engineering, Wuhan University of Technology, Wuhan, China
| | - Jianli Wang
- Institute for Superconducting and Electronic Materials, Australian Institute for Innovative Materials, University of Wollongong, Wollongong, NSW, Australia
| | - Qinghu Guo
- State Key Laboratory of Silicate Materials for Architectures, Center for Smart Materials and Device Integration, Wuhan University of Technology, Wuhan, China
| | - Bei Li
- State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, School of Materials Science and Engineering, Wuhan University of Technology, Wuhan, China
| | - Huajun Sun
- State Key Laboratory of Silicate Materials for Architectures, Center for Smart Materials and Device Integration, Wuhan University of Technology, Wuhan, China
| | - Qinfen Gu
- Australian Synchrotron (ANSTO), Clayton, Australia
| | - Hua Hao
- State Key Laboratory of Silicate Materials for Architectures, Center for Smart Materials and Device Integration, Wuhan University of Technology, Wuhan, China
| | - Qiang Shen
- State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, School of Materials Science and Engineering, Wuhan University of Technology, Wuhan, China.
| | - Jinsong Wu
- State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, School of Materials Science and Engineering, Wuhan University of Technology, Wuhan, China.
| | - Xiaozhou Liao
- School of Aerospace, Mechanical and Mechatronic Engineering, The University of Sydney, Sydney, NSW, Australia
| | - Simon P Ringer
- School of Aerospace, Mechanical and Mechatronic Engineering, The University of Sydney, Sydney, NSW, Australia
| | - Hanxing Liu
- State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, School of Materials Science and Engineering, Wuhan University of Technology, Wuhan, China
- International School of Materials Science and Engineering, Wuhan University of Technology, Wuhan, China
| | - Lianmeng Zhang
- State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, School of Materials Science and Engineering, Wuhan University of Technology, Wuhan, China
| | - Wen Chen
- State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, School of Materials Science and Engineering, Wuhan University of Technology, Wuhan, China
| | - Fei Li
- Electronic Materials Research Laboratory, Key Laboratory of the Ministry of Education and International Center for Dielectric Research, Xi'an Jiaotong University, Xi'an, China.
| | - Shujun Zhang
- Institute for Superconducting and Electronic Materials, Australian Institute for Innovative Materials, University of Wollongong, Wollongong, NSW, Australia.
| |
Collapse
|
23
|
Mosiman DS, Chen YS, Yang L, Hawkett B, Ringer SP, Mariñas BJ, Cairney JM. Atom Probe Tomography of Encapsulated Hydroxyapatite Nanoparticles. Small Methods 2021; 5:e2000692. [PMID: 34927889 DOI: 10.1002/smtd.202000692] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Revised: 10/19/2020] [Indexed: 06/14/2023]
Abstract
Hydroxyapatite nanoparticles (HAP NPs) are important for medicine, bioengineering, catalysis, and water treatment. However, current understanding of the nanoscale phenomena that confer HAP NPs their many useful properties is limited by a lack of information about the distribution of the atoms within the particles. Atom probe tomography (APT) has the spatial resolution and chemical sensitivity for HAP NP characterization, but difficulties in preparing the required needle-shaped samples make the design of these experiments challenging. Herein, two techniques are developed to encapsulate HAP NPs and prepare them into APT tips. By sputter-coating gold or the atomic layer deposition of alumina for encapsulation, partially fluoridated HAP NPs are successfully characterized by voltage- or laser-pulsing APT, respectively. Analyses reveal that significant tradeoffs exist between encapsulant methods/materials for HAP characterization and that selection of a more robust approach will require additional technique development. This work serves as an essential starting point for advancing knowledge about the nanoscale spatiochemistry of HAP NPs.
Collapse
Affiliation(s)
- Daniel S Mosiman
- Australian Centre for Microscopy and Microanalysis, The University of Sydney, Sydney, New South Wales, 2006, Australia
- Safe Global Water Institute, Department of Civil and Environmental Engineering, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
| | - Yi-Sheng Chen
- Australian Centre for Microscopy and Microanalysis, The University of Sydney, Sydney, New South Wales, 2006, Australia
- School of Aerospace Mechanical and Mechatronic Engineering, The University of Sydney, Sydney, New South Wales, 2006, Australia
| | - Limei Yang
- Australian Centre for Microscopy and Microanalysis, The University of Sydney, Sydney, New South Wales, 2006, Australia
| | - Brian Hawkett
- Key Centre for Polymer Colloids School of Chemistry, The University of Sydney, Sydney, New South Wales, 2006, Australia
| | - Simon P Ringer
- Australian Centre for Microscopy and Microanalysis, The University of Sydney, Sydney, New South Wales, 2006, Australia
- School of Aerospace Mechanical and Mechatronic Engineering, The University of Sydney, Sydney, New South Wales, 2006, Australia
| | - Benito J Mariñas
- Safe Global Water Institute, Department of Civil and Environmental Engineering, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
| | - Julie M Cairney
- Australian Centre for Microscopy and Microanalysis, The University of Sydney, Sydney, New South Wales, 2006, Australia
- School of Aerospace Mechanical and Mechatronic Engineering, The University of Sydney, Sydney, New South Wales, 2006, Australia
| |
Collapse
|
24
|
Ceguerra AV, Breen AJ, Cairney JM, Ringer SP, Gorman BP. Integrative Atom Probe Tomography Using Scanning Transmission Electron Microscopy-Centric Atom Placement as a Step Toward Atomic-Scale Tomography. Microsc Microanal 2021; 27:140-148. [PMID: 33468273 DOI: 10.1017/s1431927620024873] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Current reconstruction methodologies for atom probe tomography (APT) contain serious geometric artifacts that are difficult to address due to their reliance on empirical factors to generate a reconstructed volume. To overcome this limitation, a reconstruction technique is demonstrated where the analyzed volume is instead defined by the specimen geometry and crystal structure as determined by transmission electron microscopy (TEM) and diffraction acquired before and after APT analysis. APT data are reconstructed using a bottom-up approach, where the post-APT TEM image is used to define the substrate upon which APT detection events are placed. Transmission electron diffraction enables the quantification of the relationship between atomic positions and the evaporated specimen volume. Using an example dataset of ZnMgO:Ga grown epitaxially on c-plane sapphire, a volume is reconstructed that has the correct geometry and atomic spacings in 3D. APT data are thus reconstructed in 3D without using empirical parameters for the reverse projection reconstruction algorithm.
Collapse
Affiliation(s)
- Anna V Ceguerra
- Australian Centre for Microscopy & Microanalysis (ACMM), The University of Sydney, Sydney, NSW2006, Australia
- School of Aerospace, Mechanical and Mechatronic Engineering (AMME), The University of Sydney, Sydney, NSW2006, Australia
| | - Andrew J Breen
- Australian Centre for Microscopy & Microanalysis (ACMM), The University of Sydney, Sydney, NSW2006, Australia
- School of Aerospace, Mechanical and Mechatronic Engineering (AMME), The University of Sydney, Sydney, NSW2006, Australia
| | - Julie M Cairney
- Australian Centre for Microscopy & Microanalysis (ACMM), The University of Sydney, Sydney, NSW2006, Australia
- School of Aerospace, Mechanical and Mechatronic Engineering (AMME), The University of Sydney, Sydney, NSW2006, Australia
| | - Simon P Ringer
- Australian Centre for Microscopy & Microanalysis (ACMM), The University of Sydney, Sydney, NSW2006, Australia
- School of Aerospace, Mechanical and Mechatronic Engineering (AMME), The University of Sydney, Sydney, NSW2006, Australia
| | - Brian P Gorman
- Department of Metallurgical and Materials Engineering, Colorado School of Mines, Golden, CO80401, USA
| |
Collapse
|
25
|
Chen Z, Li F, Huang Q, Liu F, Wang F, Ringer SP, Luo H, Zhang S, Chen LQ, Liao X. Giant tuning of ferroelectricity in single crystals by thickness engineering. Sci Adv 2020; 6:6/42/eabc7156. [PMID: 33055166 PMCID: PMC7556833 DOI: 10.1126/sciadv.abc7156] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Accepted: 08/28/2020] [Indexed: 06/11/2023]
Abstract
Thickness effect and mechanical tuning behavior such as strain engineering in thin-film ferroelectrics have been extensively studied and widely used to tailor the ferroelectric properties. However, this is never the case in freestanding single crystals, and conclusions from thin films cannot be duplicated because of the differences in the nature and boundary conditions of the thin-film and freestanding single-crystal ferroelectrics. Here, using in situ biasing transmission electron microscopy, we studied the thickness-dependent domain switching behavior and predicted the trend of ferroelectricity in nanoscale materials induced by surface strain. We discovered that sample thickness plays a critical role in tailoring the domain switching behavior and ferroelectric properties of single-crystal ferroelectrics, arising from the huge surface strain and the resulting surface reconstruction. Our results provide important insights in tuning polarization/domain of single-crystal ferroelectric via sample thickness engineering.
Collapse
Affiliation(s)
- Zibin Chen
- School of Aerospace, Mechanical and Mechatronic Engineering, The University of Sydney, Sydney, NSW 2006, Australia.
| | - Fei Li
- Electronic Materials Research Laboratory, Key Laboratory of the Ministry of Education, Xi'an Jiaotong University, Xi'an 710049, China
| | - Qianwei Huang
- School of Aerospace, Mechanical and Mechatronic Engineering, The University of Sydney, Sydney, NSW 2006, Australia
| | - Fei Liu
- Key Laboratory of Optoelectronic Material and Device, Department of Physics, Shanghai Normal University, Shanghai 200234, China
| | - Feifei Wang
- Key Laboratory of Optoelectronic Material and Device, Department of Physics, Shanghai Normal University, Shanghai 200234, China
| | - Simon P Ringer
- School of Aerospace, Mechanical and Mechatronic Engineering, The University of Sydney, Sydney, NSW 2006, Australia
| | - Haosu Luo
- Key Laboratory of Inorganic Functional Materials and Devices, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 201899, China
| | - Shujun Zhang
- Institute for Superconducting and Electronic Materials, Australian Institute of Innovative Materials, University of Wollongong, Wollongong, NSW 2522, Australia.
| | - Long-Qing Chen
- Materials Research Institute, Department of Materials Science and Engineering, The Pennsylvania State University, University Park, PA 16802, USA
| | - Xiaozhou Liao
- School of Aerospace, Mechanical and Mechatronic Engineering, The University of Sydney, Sydney, NSW 2006, Australia.
| |
Collapse
|
26
|
Nomoto K, Sugimoto H, Ceguerra AV, Fujii M, Ringer SP. 3D microstructure analysis of silicon-boron phosphide mixed nanocrystals. Nanoscale 2020; 12:7256-7262. [PMID: 32196060 DOI: 10.1039/d0nr01023e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
The microstructure of boron (B) and phosphorus (P) codoped silicon (Si) nanocrystals (NCs), cubic boron phosphide (BP) NCs and their mixed NCs (BxSiyPz NCs) has been studied using atom probe tomography (APT), transmission electron microscopy (TEM), and Raman scattering spectroscopy. The BxSiyPz NCs inherit superior properties of B and P codoped Si NCs such as high dispersibility in aqueous media and near infrared (NIR) luminescence and those of cubic BP NCs such as high chemical stability. The microanalyses revealed that BxSiyPz NCs are composed of a crystalline core and an amorphous shell. The core possesses a lattice constant between that of Si (diamond-cubic) and BP (cubic). The amorphous shell is comprised of B, Si and P, though the composition is not uniform and there are local B-rich, Si-rich and P-rich domains connected contiguously. The amorphous shell is proposed to be responsible for their superior chemical properties such as high dispersibility in polar solvents and high resistance to acids, and the crystalline core is responsible for the stable NIR luminescence.
Collapse
Affiliation(s)
- Keita Nomoto
- The University of Sydney, Australian Centre for Microscopy & Microanalysis, and School of Aerospace, Mechanical and Mechatronic Engineering, 2006 Sydney, Australia.
| | | | | | | | | |
Collapse
|
27
|
Fang R, Cui X, Stampfl C, Ringer SP, Zheng R. High mobility in α-phosphorene isostructures with low deformation potential. Phys Chem Chem Phys 2020; 22:2276-2282. [PMID: 31919485 DOI: 10.1039/c9cp05828a] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The exceptionally low deformation potential is proposed as the key determinant for the high carrier mobility in α-phosphorene. This is related to its unique corrugated two-dimensional structure. Herein, we present a systematic first-principles density functional theory study on ten α-phosphorene isostructures by calculating the three key parameters of the carrier mobility. An electron mobility in the armchair direction with a value comparable to α-phosphorene is found in α-PAs, α-PCH, and α-AsCH, due to the structure-caused low deformation potential. The highest carrier mobility is predicted in α-graphane because of a two-orders-of-magnitude smaller deformation potential than the other isostructures. The low deformation potential can be correlated to the separation of charge carriers from neighbouring unit cells. This study highlights a feasible route to generating high mobility materials through deformation potential engineering.
Collapse
Affiliation(s)
- Ruhao Fang
- School of Physics, The University of Sydney, New South Wales 2006, Australia. and Nano Institute, The University of Sydney, New South Wales 2006, Australia
| | - Xiangyuan Cui
- School of Aerospace, Mechanical and Mechatronic Engineering, The University of Sydney, New South Wales 2006, Australia. and Australian Centre for Microscopy and Microanalysis, The University of Sydney, New South Wales 2006, Australia
| | - Catherine Stampfl
- School of Physics, The University of Sydney, New South Wales 2006, Australia. and Nano Institute, The University of Sydney, New South Wales 2006, Australia
| | - Simon P Ringer
- School of Aerospace, Mechanical and Mechatronic Engineering, The University of Sydney, New South Wales 2006, Australia. and Australian Centre for Microscopy and Microanalysis, The University of Sydney, New South Wales 2006, Australia
| | - Rongkun Zheng
- School of Physics, The University of Sydney, New South Wales 2006, Australia. and Nano Institute, The University of Sydney, New South Wales 2006, Australia and Australian Centre for Microscopy and Microanalysis, The University of Sydney, New South Wales 2006, Australia
| |
Collapse
|
28
|
Yun F, Swain MV, Chen H, Cairney J, Qu J, Sha G, Liu H, Ringer SP, Han Y, Liu L, Zhang X, Zheng R. Nanoscale pathways for human tooth decay - Central planar defect, organic-rich precipitate and high-angle grain boundary. Biomaterials 2019; 235:119748. [PMID: 31978841 DOI: 10.1016/j.biomaterials.2019.119748] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2019] [Revised: 12/02/2019] [Accepted: 12/25/2019] [Indexed: 02/01/2023]
Abstract
Understanding the pathways and mechanisms of human tooth decay is central to the development of both prophylaxes and treatments, but only limited information is presently available about the initiation of caries at the nanoscale. By combining atom probe tomography and high-resolution electron microscopy, we have found three distinct initial sites for human dental enamel dissolution: a) along the central dark line (CDL) within carbonated apatite nanocrystals, b) at organic-rich precipitates and c) along high-angle grain boundaries. 3D maps of the atoms within hydroxyapatite nanocrystallites in sound and naturally-decayed human dental enamel reveal a higher concentration of Mg and Na in the CDL. The CDL is therefore thought to provide a pathway for the exchange of ions during demineralization and remineralization. Mg and Na enrichment of the CDL also suggests that it is associated with the ribbon-like organic-rich precursor in amelogenesis. Organic-rich precipitates and high-angle grain boundaries were also shown to be more vulnerable to corrosion while low-angle grain boundaries remained intact. This is attributed to the lower crystallinity in these regions.
Collapse
Affiliation(s)
- Fan Yun
- School of Physics, The University of Sydney, NSW, 2006, Australia; Australian Center for Microscopy and Microanalysis, The University of Sydney, NSW, 2006, Australia; The University of Sydney Nano Institute, The University of Sydney, Sydney, NSW, 2006, Australia
| | - Michael V Swain
- School of Aerospace, Mechanical and Mechatronic Engineering, the University of Sydney, Sydney, NSW, 2006, Australia
| | - Hansheng Chen
- School of Physics, The University of Sydney, NSW, 2006, Australia; Australian Center for Microscopy and Microanalysis, The University of Sydney, NSW, 2006, Australia; The University of Sydney Nano Institute, The University of Sydney, Sydney, NSW, 2006, Australia
| | - Julie Cairney
- Australian Center for Microscopy and Microanalysis, The University of Sydney, NSW, 2006, Australia; The University of Sydney Nano Institute, The University of Sydney, Sydney, NSW, 2006, Australia; School of Aerospace, Mechanical and Mechatronic Engineering, the University of Sydney, Sydney, NSW, 2006, Australia
| | - Jiangtao Qu
- School of Physics, The University of Sydney, NSW, 2006, Australia; Australian Center for Microscopy and Microanalysis, The University of Sydney, NSW, 2006, Australia; The University of Sydney Nano Institute, The University of Sydney, Sydney, NSW, 2006, Australia
| | - Gang Sha
- School of Materials Science and Engineering, Herbert Gleiter Institute of Nanoscience, Nanjing University of Science and Technology, Nanjing, Jiangsu, 210094, China
| | - Hongwei Liu
- Australian Center for Microscopy and Microanalysis, The University of Sydney, NSW, 2006, Australia
| | - Simon P Ringer
- The University of Sydney Nano Institute, The University of Sydney, Sydney, NSW, 2006, Australia; School of Aerospace, Mechanical and Mechatronic Engineering, the University of Sydney, Sydney, NSW, 2006, Australia
| | - Yu Han
- Physical Sciences and Engineering Division, King Abdullah University of Science and Technology, Thuwal, 23955-6900, Saudi Arabia
| | - Lingmei Liu
- Physical Sciences and Engineering Division, King Abdullah University of Science and Technology, Thuwal, 23955-6900, Saudi Arabia
| | - Xixiang Zhang
- Physical Sciences and Engineering Division, King Abdullah University of Science and Technology, Thuwal, 23955-6900, Saudi Arabia
| | - Rongkun Zheng
- School of Physics, The University of Sydney, NSW, 2006, Australia; Australian Center for Microscopy and Microanalysis, The University of Sydney, NSW, 2006, Australia; The University of Sydney Nano Institute, The University of Sydney, Sydney, NSW, 2006, Australia.
| |
Collapse
|
29
|
Affiliation(s)
- Xiang-Yuan Cui
- Australian Centre for Microscopy and Microanalysis, and School of Aerospace, Mechanical and Mechatronic Engineering, The University of Sydney, Sydney, NSW 2006, Australia
| | - Simon P. Ringer
- Australian Centre for Microscopy and Microanalysis, and School of Aerospace, Mechanical and Mechatronic Engineering, The University of Sydney, Sydney, NSW 2006, Australia
| | - Gang Wang
- Materials Microstructures Laboratory, University of Shanghai, Shanghai, China
| | - Z. H. Stachurski
- Research School of Engineering, CECS, Australian National University, ACT 2600, Australia
| |
Collapse
|
30
|
Ding X, Cui X, Xiao C, Luo X, Bao N, Rusydi A, Yu X, Lu Z, Du Y, Guan X, Tseng LT, Lee WT, Ahmed S, Zheng R, Liu T, Wu T, Ding J, Suzuki K, Lauter V, Vinu A, Ringer SP, Yi JB. Confinement-Induced Giant Spin-Orbit-Coupled Magnetic Moment of Co Nanoclusters in TiO 2 Films. ACS Appl Mater Interfaces 2019; 11:43781-43788. [PMID: 31660716 DOI: 10.1021/acsami.9b15823] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
High magnetization materials are in great demand for the fabrication of advanced multifunctional magnetic devices. Notwithstanding this demand, the development of new materials with these attributes has been relatively slow. In this work, we propose a new strategy to achieve high magnetic moments above room temperature. Our material engineering approach invoked the embedding of magnetic nanoclusters in an oxide matrix. By precisely controlling pulsed laser deposition parameters, Co nanoclusters are formed in a 5 at % Co-TiO2 film. The presence of these nanoclusters was confirmed using transmission electron microscopy, energy-dispersive X-ray spectroscopy, and X-ray absorption fine structure. The film exhibits a very high saturation magnetization of 99 emu/cm3. Detailed studies using X-ray magnetic circular dichroism confirm that Co has an enhanced magnetic moment of 3.5 μB/atom, while the Ti and O also contribute to the magnetic moments. First-principles calculations supported our hypothesis that the metallic Co nanoclusters surrounded by a TiO2 matrix can exhibit both large spin and orbital moments. Moreover, a quantum confinement effect results in a high Curie temperature for the embedded Co nanoclusters. These findings reveal that 1-2 nm nanoclusters that are quantum confined can exhibit very large magnetic moments above room temperature, representing a promising advance for the design of new high magnetization materials.
Collapse
Affiliation(s)
- Xiang Ding
- School of Materials Science and Engineering , UNSW Sydney , Kensington , NSW 2052 , Australia
| | | | - Chi Xiao
- Department of Physics and Singapore Synchrotron Light Source , National University of Singapore , 119077 Singapore
| | - Xi Luo
- School of Materials Science and Engineering , UNSW Sydney , Kensington , NSW 2052 , Australia
| | | | - Andrivo Rusydi
- Department of Physics and Singapore Synchrotron Light Source , National University of Singapore , 119077 Singapore
| | | | | | - Yonghua Du
- Institute of Chemical and Engineering Science , Agency for Science, Technology and Research (A*STAR) , 1 Pesek Road , Jurong Island, 627833 Singapore
| | - Xinwei Guan
- School of Materials Science and Engineering , UNSW Sydney , Kensington , NSW 2052 , Australia
- Physical Sciences and Engineering Division , King Abdullah University of Science and Technology , Thuwal 23955-6900 , Saudi Arabia
| | - Li-Ting Tseng
- School of Materials Science and Engineering , UNSW Sydney , Kensington , NSW 2052 , Australia
| | - Wai Tung Lee
- Bragg Institute , ANSTO , New Illawarra Road , Lucas Heights, Sydney , NSW 2234 , Australia
| | - Sohail Ahmed
- School of Materials Science and Engineering , UNSW Sydney , Kensington , NSW 2052 , Australia
| | | | - Tao Liu
- Karls Tech GmbH , Fischreiher Strasse 3 , Karlsruhe 76187 , Germany
| | - Tom Wu
- School of Materials Science and Engineering , UNSW Sydney , Kensington , NSW 2052 , Australia
| | | | - Kiyonori Suzuki
- Department of Materials Science and Engineering , Monash University , Melbourne , Victoria 3800 , Australia
| | - Valeria Lauter
- Neutron Scattering Division, Neutron Sciences Directorate , Oak Ridge National Laboratory , Oak Ridge , Tennessee 37831 , United States
| | - Ajayan Vinu
- Global Innovative Center for Advanced Nanomaterials, School of Engineering , University of Newcastle , Callaghan , NSW 2308 , Australia
| | | | - Jia Bao Yi
- Global Innovative Center for Advanced Nanomaterials, School of Engineering , University of Newcastle , Callaghan , NSW 2308 , Australia
| |
Collapse
|
31
|
Theska F, Ceguerra AV, Turk C, Breen AJ, Ringer SP, Primig S. Correlative study of lattice imperfections in long-range ordered, nano-scale domains in a Fe-Co-Mo alloy. Ultramicroscopy 2019; 204:91-100. [PMID: 31132736 DOI: 10.1016/j.ultramic.2019.05.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2019] [Revised: 04/29/2019] [Accepted: 05/12/2019] [Indexed: 10/26/2022]
Abstract
Recent advancements in data mining methods in atom probe microscopy have enabled new quantitative chemical and microstructural characterization beyond the standard three-dimensional reconstruction. For example, spatial distribution maps have been developed to enable visualisation of the local lattice occupation of a selected region of interest. However, the precision of such studies yet remains unknown as correlation with complementary methods would be required. Therefore, a correlative study of atom probe microscopy, neutron diffraction and microstructural modelling of long-range ordered, nano-scale domains in a well-researched Fe-Co-Mo Maraging-type steel is presented here. Its microstructure consists of Mo-enriched µ-phase (Fe,Co)7Mo6 particles embedded into a body-centred cubic FeCo matrix. Previous research has shown that under slow cooling conditions, this matrix partially decomposes into nano-scale B2 long-range ordered domains surrounded by disordered regions, resulting in reduced toughness in potential cutting applications. Usually, a long-range order parameter S referring to ideal B2 long-range order is assumed within such domains according to neutron diffraction. However, atom probe microscopy and modelling results presented in the current study indicate lattice imperfections with a partial substitution of atoms on the Fe- and Co-sublattices. After considering preferential retention effects during the atom probe experiment, a model unit cell is presented to define the observed imperfect B2 long-range order as pseudo-D03 long-range order, and the potential impact on the materials properties is discussed.
Collapse
Affiliation(s)
- F Theska
- School of Materials Science & Engineering, UNSW Sydney, NSW 2052, Australia
| | - A V Ceguerra
- Australian Centre for Microscopy & Microanalysis and School of Aerospace, Mechanical and Mechatronic Engineering, The University of Sydney, NSW 2006, Australia
| | - C Turk
- Voestalpine Böhler Edelstahl GmbH & Co KG, Mariazellerstraße 25, 8605 Kapfenberg, Austria
| | - A J Breen
- Australian Centre for Microscopy & Microanalysis and School of Aerospace, Mechanical and Mechatronic Engineering, The University of Sydney, NSW 2006, Australia; Department of Microstructure Physics and Alloy Design, Max-Planck-Institute for Iron Research, 40237 Düsseldorf, Germany
| | - S P Ringer
- Australian Centre for Microscopy & Microanalysis and School of Aerospace, Mechanical and Mechatronic Engineering, The University of Sydney, NSW 2006, Australia
| | - S Primig
- School of Materials Science & Engineering, UNSW Sydney, NSW 2052, Australia.
| |
Collapse
|
32
|
Qu J, Chen H, Khan M, Yun F, Cui X, Ringer SP, Cairney JM, Zheng R. Quantitative Determination of How Growth Conditions Affect the 3D Composition of InGaAs Nanowires. Microsc Microanal 2019; 25:524-531. [PMID: 30773161 DOI: 10.1017/s1431927619000114] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Covering a broad optical spectrum, ternary InxGa1-xAs nanowires, grown by bottom-up methods, have been receiving increasing attention due to the tunability of the bandgap via In composition modulation. However, inadequate knowledge about the correlation between growth and properties restricts our ability to take advantage of this phenomenon for optoelectronic applications. Here, three different InGaAs nanowires were grown under different experimental conditions and atom probe tomography was used to quantify their composition, allowing the direct observation of the nanowire composition associated with the different growth conditions.
Collapse
Affiliation(s)
- Jiangtao Qu
- School of Physics,Camperdown, New South Wales,Australia
| | - Hansheng Chen
- School of Physics,Camperdown, New South Wales,Australia
| | - Mansoor Khan
- School of Physics,Camperdown, New South Wales,Australia
| | - Fan Yun
- School of Physics,Camperdown, New South Wales,Australia
| | - Xiangyuan Cui
- Aerospace, Mechanical and Mechatronic Engineering, the University of Sydney,2006 NSW,Australia
| | - Simon P Ringer
- Aerospace, Mechanical and Mechatronic Engineering, the University of Sydney,2006 NSW,Australia
| | - Julie M Cairney
- Aerospace, Mechanical and Mechatronic Engineering, the University of Sydney,2006 NSW,Australia
| | - Rongkun Zheng
- School of Physics,Camperdown, New South Wales,Australia
| |
Collapse
|
33
|
Day AC, Ceguerra AV, Ringer SP. Introducing a Crystallography-Mediated Reconstruction (CMR) Approach to Atom Probe Tomography. Microsc Microanal 2019; 25:288-300. [PMID: 30712521 DOI: 10.1017/s1431927618015593] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Current approaches to reconstruction in atom probe tomography produce results that exhibit substantial distortions throughout the analysis depth. This is largely because of the need to apply a multitude of assumptions when estimating the evolution of the tip shape, and other pseudo-empirical reconstruction factors, which vary both across the face of the tip and throughout the analysis depth. We introduce a new crystallography-mediated reconstruction to improve the spatial accuracy and dramatically reduce these in-depth variations. To achieve this, we developed a barycentric transform to directly relate atomic positions in detector space to real space. This is mediated by novel crystallographic analysis techniques, including: (1) calculating the orientation of a crystal directly from the field evaporation map, (2) tracking pole locations throughout the evaporation sequence, and (3) accounting for the evolving tip radius in a manner that removes the dependence on the geometric field factor. By improving the in-depth spatial accuracy of the atom probe reconstruction, a greater accuracy of the atomic neighborhood relationships is available. This is critical in modern materials science and engineering, where an understanding of the solid solution architecture, precipitate dispersions, and descriptions of the interfaces between phases or grains are key inputs to microstructure-property relationships.
Collapse
Affiliation(s)
- Alec C Day
- Australian Centre for Microscopy & Microanalysis, and School of Aerospace, Mechanical and Mechatronic Engineering,The University of Sydney,Sydney,NSW 2006,Australia
| | - Anna V Ceguerra
- Australian Centre for Microscopy & Microanalysis, and School of Aerospace, Mechanical and Mechatronic Engineering,The University of Sydney,Sydney,NSW 2006,Australia
| | - Simon P Ringer
- Australian Centre for Microscopy & Microanalysis, and School of Aerospace, Mechanical and Mechatronic Engineering,The University of Sydney,Sydney,NSW 2006,Australia
| |
Collapse
|
34
|
Ceguerra AV, Day AC, Ringer SP. Assessing the Spatial Accuracy of the Reconstruction in Atom Probe Tomography and a New Calibratable Adaptive Reconstruction. Microsc Microanal 2019; 25:309-319. [PMID: 31018880 DOI: 10.1017/s1431927619000369] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
We define a measure for the accuracy of tomographic reconstruction in atom probe tomography, named here the spatial error index. We demonstrate that this index can be used to compare rigorously the spatial accuracy of various different approaches to the calculation of tomographic reconstruction. This is useful, for example, to evaluate the performance of alternate tomographic reconstruction approaches, and ensures that the comparisons are independent of individual data quality or other instrumental parameters. We then introduce a new "adaptive reconstruction" formalism that uses a progression of reconstruction parameters based on a per-atom correction from the cube root of the inverse of the voltage, along with linear correction factors linked to the evaporation sequence. We apply the measure for spatial accuracy to this new reconstruction protocol.
Collapse
Affiliation(s)
- Anna V Ceguerra
- Australian Centre for Microscopy & Microanalysis, and School of Aerospace, Mechanical and Mechatronic Engineering,The University of Sydney,Sydney, NSW 2006,Australia
| | - Alec C Day
- Australian Centre for Microscopy & Microanalysis, and School of Aerospace, Mechanical and Mechatronic Engineering,The University of Sydney,Sydney, NSW 2006,Australia
| | - Simon P Ringer
- Australian Centre for Microscopy & Microanalysis, and School of Aerospace, Mechanical and Mechatronic Engineering,The University of Sydney,Sydney, NSW 2006,Australia
| |
Collapse
|
35
|
Fang R, Cui X, Stampfl C, Ringer SP, Zheng R. Negative Poisson's ratio in 2D life-boat structured crystals. Nanoscale Adv 2019; 1:1117-1123. [PMID: 36133211 PMCID: PMC9473230 DOI: 10.1039/c8na00352a] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2018] [Accepted: 12/11/2018] [Indexed: 06/10/2023]
Abstract
Two-dimensional auxetic materials with negative Poisson's ratio expand in response to a tensile strain in cross-section. Such counter-intuitive behaviours have been mainly ascribed to concave structures with ideal rigid ball-stick models. Here, based on first-principles calculations, we systematically analyze the mechanical behaviours of three life-boat structured two-dimensional (2D) materials and report two new auxetic materials: δ-arsenic and δ-graphane. The calculated Poisson's ratio values are correlated with Young's modulus, cohesive energy, and valence shell electron pair repulsion of isostructures. Combining with previous research, we provide a self-consistent explanation of the origin of the 2D in-plane negative Poisson's ratio and an algorithmic route to discover new auxetic materials by comparing the energy restored in bond rotation and stretch.
Collapse
Affiliation(s)
- Ruhao Fang
- School of Physics, The University of Sydney New South Wales 2006 Australia
- Nano Institute, The University of Sydney Sydney New South Wales 2006 Australia
| | - Xiangyuan Cui
- School of Aerospace, Mechanical and Mechatronic Enigineering, The University of Sydney Sydney New South Wales 2006 Australia
- Australian Centre for Microscopy and Microanalysis, The University of Sydney Sydney New South Wales 2006 Australia
| | - Catherine Stampfl
- School of Physics, The University of Sydney New South Wales 2006 Australia
| | - Simon P Ringer
- School of Aerospace, Mechanical and Mechatronic Enigineering, The University of Sydney Sydney New South Wales 2006 Australia
- Australian Centre for Microscopy and Microanalysis, The University of Sydney Sydney New South Wales 2006 Australia
| | - Rongkun Zheng
- School of Physics, The University of Sydney New South Wales 2006 Australia
- Australian Centre for Microscopy and Microanalysis, The University of Sydney Sydney New South Wales 2006 Australia
- Nano Institute, The University of Sydney Sydney New South Wales 2006 Australia
| |
Collapse
|
36
|
Khan MA, Bian P, Qu J, Chen H, Liu H, Foley M, Yao Y, Ringer SP, Zheng R. Non-destructive analysis on nano-textured surface of the vertical LED for light enhancement. Ultramicroscopy 2018; 196:1-9. [PMID: 30267990 DOI: 10.1016/j.ultramic.2018.09.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2018] [Revised: 07/10/2018] [Accepted: 09/12/2018] [Indexed: 10/28/2022]
Abstract
In this work, the nano-textured surface of a GaN-based vertical light emitting diode (VLED) is characterized using a unified framework of non-destructive techniques (NDT) incorporating scanning electron microscopy (SEM), atomic force microscopy (AFM), Raman spectroscopy, Photoluminescence (PL), and X-ray diffraction (XRD) to optimize the light output efficiency. The surface roughness of ∼300 nm is revealed by AFM. Compressive stress-state of 0.667 GPa in the GaN surface is indicated by the E2(high) and A1(LO) phonon peak values at 569 cm-1 and 736 cm-1, respectively, in Raman spectrum and the wavelength at 442 nm rather 450 nm in PL spectrum. Without damaging the LED, surface analysis by NDT helps to advance the understanding of the optimized angular light redistribution subject to the high-roughness surface and the negative impacts of the stress induced at the top GaN layer, which leads to the optical efficiency degradation of the VLED. Furthermore, the impact of texturing on underneath n-GaN and MQWs layers is investigated via SEM-based transmission Kikuchi diffraction (TKD) and aberration-corrected scanning transmission electron microscopy (AC-STEM) and revealed a smooth surface morphology and good crystalline quality, indicating that the etch-induced damage by texture engineering does not impair the active region of the VLED. Accordingly, prospective optimizations are suggested in the context of surface engineering for light enhancement in VLEDs.
Collapse
Affiliation(s)
- Mansoor Ali Khan
- School of Physics, The University of Sydney, Sydney, NSW 2006, Australia; The University of Sydney Nano Institute, The University of Sydney, Sydney, NSW 2006, Australia; Australian Centre for Microscopy and Microanalysis, The University of Sydney, Sydney, NSW 2006, Australia
| | - Pengju Bian
- School of Physics, The University of Sydney, Sydney, NSW 2006, Australia; The University of Sydney Nano Institute, The University of Sydney, Sydney, NSW 2006, Australia; Australian Centre for Microscopy and Microanalysis, The University of Sydney, Sydney, NSW 2006, Australia
| | - Jiangtao Qu
- School of Physics, The University of Sydney, Sydney, NSW 2006, Australia; The University of Sydney Nano Institute, The University of Sydney, Sydney, NSW 2006, Australia; Australian Centre for Microscopy and Microanalysis, The University of Sydney, Sydney, NSW 2006, Australia
| | - Hansheng Chen
- School of Physics, The University of Sydney, Sydney, NSW 2006, Australia; The University of Sydney Nano Institute, The University of Sydney, Sydney, NSW 2006, Australia; Australian Centre for Microscopy and Microanalysis, The University of Sydney, Sydney, NSW 2006, Australia
| | - Hongwei Liu
- Australian Centre for Microscopy and Microanalysis, The University of Sydney, Sydney, NSW 2006, Australia
| | - Matthew Foley
- Australian Centre for Microscopy and Microanalysis, The University of Sydney, Sydney, NSW 2006, Australia
| | - Yin Yao
- Electron Microscope Unit, University of New South Wales, Sydney, NSW 2052, Australia
| | - S P Ringer
- School of Aerospace, Mechanical and Mechatronic Engineering, The University of Sydney, Sydney, NSW 2006, Australia
| | - Rongkun Zheng
- School of Physics, The University of Sydney, Sydney, NSW 2006, Australia; The University of Sydney Nano Institute, The University of Sydney, Sydney, NSW 2006, Australia; Australian Centre for Microscopy and Microanalysis, The University of Sydney, Sydney, NSW 2006, Australia.
| |
Collapse
|
37
|
Li W, Wang Y, Cui XY, Yu S, Li Y, Hu Y, Zhu M, Zheng R, Ringer SP. Crystal Facet Effects on Nanomagnetism of Co 3O 4. ACS Appl Mater Interfaces 2018; 10:19235-19247. [PMID: 29706073 DOI: 10.1021/acsami.8b03934] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
The magnetic performance of nanomaterials depends on size, shape, and surface of the nanocrystals. Here, the exposed crystal planes of Co3O4 nanocrystals were analyzed to research the dependence of magnetic properties on the configuration environment of the ions exposed on different surfaces. The Co3O4 nanocrystals with exposed (1 0 0), (1 1 0), (1 1 1), and (1 1 2) planes were synthesized using a hydrothermal method in the shapes of nanocube, nanorod, hexagonal nanoplatelet, and nanolaminar, respectively. Ferromagnetic performance was detected in the (1 0 0) and (1 1 1) plane-exposed samples. First-principles calculation results indicate that unlike the nonmagnetic nature in the bulk, the Co3+ ions exposed on or close to the surface possess sizable magnetic moments because of the variation of coordination numbers and lattice distortion, which is responsible for the ferromagnetic-like behavior. The (1 1 0)-exposed sample keeps the natural antiferromagnetic behavior of bulk Co3O4 because either the surface Co3+ ions have no magnetic moments or their moments are in antiferromagnetic coupling. The (1 1 2)-exposed sample also displays antiferromagnetism because the interaction distances between the magnetized Co3+ ions are too long to form effective ferromagnetic coupling.
Collapse
Affiliation(s)
- Wenxian Li
- Institute of Materials, School of Materials Science and Engineering , Shanghai University , 149 Yanchang Road , Shanghai 200072 , China
- Institute for Sustainable Energy , Shanghai University , Shanghai 200444 , China
- Shanghai Key Laboratory of High Temperature Superconductors , Shanghai 200444 , China
| | - Yan Wang
- Institute of Materials, School of Materials Science and Engineering , Shanghai University , 149 Yanchang Road , Shanghai 200072 , China
| | | | - Shangjia Yu
- Institute of Materials, School of Materials Science and Engineering , Shanghai University , 149 Yanchang Road , Shanghai 200072 , China
| | - Ying Li
- Institute of Materials, School of Materials Science and Engineering , Shanghai University , 149 Yanchang Road , Shanghai 200072 , China
- Institute for Sustainable Energy , Shanghai University , Shanghai 200444 , China
| | - Yemin Hu
- Institute of Materials, School of Materials Science and Engineering , Shanghai University , 149 Yanchang Road , Shanghai 200072 , China
| | - Mingyuan Zhu
- Institute of Materials, School of Materials Science and Engineering , Shanghai University , 149 Yanchang Road , Shanghai 200072 , China
| | | | | |
Collapse
|
38
|
Ringer SP. Atomic segregation: Activity at the surface. Nat Mater 2017; 17:10-12. [PMID: 29255231 DOI: 10.1038/nmat5058] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Affiliation(s)
- Simon P Ringer
- School of Aerospace, Mechanical and Mechatronic Engineering, and the Australian Centre for Microscopy & Microanalysis, University of Sydney, New South Wales 2006, Australia
| |
Collapse
|
39
|
Abstract
The potential of C60 as a nucleic acid base (NAB) optical sensor is theoretically explored. We investigate the adsorption of four NABs, namely, adenine, cytosine, guanine, and thymine, on C60 in the gas phase. For the optimal NAB@C60 adsorption configurations, obtained using a dispersion-corrected density functional, we calculate the vis-near-ultraviolet optical response using time-dependent density functional theory. While the isolated C60 and NAB molecules do not exhibit visible optical excitation, we find that C60/NAB conjugation gives rise to distinct spectral features in the visible range. These results suggest that C60 conjugation can be applied for photodetection of individual NABs.
Collapse
Affiliation(s)
| | | | | | - C Stampfl
- School of Physics, The University of Sydney , Sydney, New South Wales 2006, Australia
| |
Collapse
|
40
|
Khan MA, Chen H, Qu J, Trimby PW, Moody S, Yao Y, Ringer SP, Zheng R. Insights into the Silver Reflection Layer of a Vertical LED for Light Emission Optimization. ACS Appl Mater Interfaces 2017; 9:24259-24272. [PMID: 28653527 DOI: 10.1021/acsami.7b04854] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
In this work, Ag as a highly reflective mirror layer of gallium nitride (GaN)-based blue vertical light-emitting diodes (VLEDs) has been systematically investigated by correlating scanning electron microscopy/energy dispersive X-ray spectroscopy/transmission Kikuchi diffraction/electron backscatter diffraction, aberration-corrected scanning transmission electron microscopy, and atomic force microscopy techniques. In the context of high-efficiency lighting, three critical aspects have been scrutinized on the nanoscale: (1) chemical diffusion, (2) grain morphology, and (3) surface topography of the Ag layer. We found that nanoscale inhomogeneous distribution of In in InGaN/GaN quantum wells (QWs), interfacial diffusion (In/Ga out-diffusion into the Ag layer and diffusion of Ag into p-GaN and QWs), and Ag agglomeration deteriorate the light reflectivity, which account for the decreased luminous efficiency in VLEDs. Meanwhile, the surface morphology and topographical analyses revealed the nanomorphology of the Ag layer, where a nanograin size of ∼300 nm with special nanotwinned boundaries and an extremely smooth surface of ∼3-4 nm are strongly desired for better reflectivity. Further, on the basis of these microscopy results, suggestions on light extraction optimization are given to improve the performance of GaN-based blue VLEDs. Our findings enable fresh and deep understanding of performance-microstructure correlation of LEDs on the nanoscale, providing guidance to the design and manufacture of high-performance LED devices.
Collapse
Affiliation(s)
| | | | | | | | | | - Yin Yao
- Electron Microscope Unit, University of New South Wales , Sydney, New South Wales 2052, Australia
| | | | | |
Collapse
|
41
|
Tawfik SA, Weston L, Cui XY, Ringer SP, Stampfl C. Near-Perfect Spin Filtering and Negative Differential Resistance in an Fe(II)S Complex. J Phys Chem Lett 2017; 8:2189-2194. [PMID: 28457138 DOI: 10.1021/acs.jpclett.7b00551] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Density functional theory and nonequilibrium Green's function calculations have been used to explore spin-resolved transport through the high-spin state of an iron(II)sulfur single molecular magnet. Our results show that this molecule exhibits near-perfect spin filtering, where the spin-filtering efficiency is above 99%, as well as significant negative differential resistance centered at a low bias voltage. The rise in the spin-up conductivity up to the bias voltage of 0.4 V is dominated by a conductive lowest unoccupied molecular orbital, and this is accompanied by a slight increase in the magnetic moment of the Fe atom. The subsequent drop in the spin-up conductivity is because the conductive channel moves to the highest occupied molecular orbital, which has a lower conductance contribution. This is accompanied by a drop in the magnetic moment of the Fe atom. These two exceptional properties, and the fact that the onset of negative differential resistance occurs at low bias voltage, suggests the potential of the molecule in nanoelectronic and nanospintronic applications.
Collapse
Affiliation(s)
| | - Leigh Weston
- Materials Department, University of California , Santa Barbara, California, United States
| | - X Y Cui
- Australian Centre for Microscopy and Microanalysis, and School of Aerospace, Mechanical and Mechatronic Engineering, The University of Sydney , New South Wales, 2006, Australia
| | - S P Ringer
- Australian Centre for Microscopy and Microanalysis, and School of Aerospace, Mechanical and Mechatronic Engineering, The University of Sydney , New South Wales, 2006, Australia
| | - C Stampfl
- School of Physics, The University of Sydney , New South Wales, 2006, Australia
| |
Collapse
|
42
|
Breen AJ, Babinsky K, Day AC, Eder K, Oakman CJ, Trimby PW, Primig S, Cairney JM, Ringer SP. Correlating Atom Probe Crystallographic Measurements with Transmission Kikuchi Diffraction Data. Microsc Microanal 2017; 23:279-290. [PMID: 28288697 DOI: 10.1017/s1431927616012605] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Correlative microscopy approaches offer synergistic solutions to many research problems. One such combination, that has been studied in limited detail, is the use of atom probe tomography (APT) and transmission Kikuchi diffraction (TKD) on the same tip specimen. By combining these two powerful microscopy techniques, the microstructure of important engineering alloys can be studied in greater detail. For the first time, the accuracy of crystallographic measurements made using APT will be independently verified using TKD. Experimental data from two atom probe tips, one a nanocrystalline Al-0.5Ag alloy specimen collected on a straight flight-path atom probe and the other a high purity Mo specimen collected on a reflectron-fitted instrument, will be compared. We find that the average minimum misorientation angle, calculated from calibrated atom probe reconstructions with two different pole combinations, deviate 0.7° and 1.4°, respectively, from the TKD results. The type of atom probe and experimental conditions appear to have some impact on this accuracy and the reconstruction and measurement procedures are likely to contribute further to degradation in angular resolution. The challenges and implications of this correlative approach will also be discussed.
Collapse
Affiliation(s)
- Andrew J Breen
- 1Australian Centre for Microscopy and Microanalysis,The University of Sydney,Sydney,NSW 2006,Australia
| | - Katharina Babinsky
- 3Department of Physical Metallurgy and Materials Testing,Montanuniversität Leoben,Franz-Josef Straße 18,8700 Leoben,Austria
| | - Alec C Day
- 1Australian Centre for Microscopy and Microanalysis,The University of Sydney,Sydney,NSW 2006,Australia
| | - K Eder
- 1Australian Centre for Microscopy and Microanalysis,The University of Sydney,Sydney,NSW 2006,Australia
| | - Connor J Oakman
- 1Australian Centre for Microscopy and Microanalysis,The University of Sydney,Sydney,NSW 2006,Australia
| | - Patrick W Trimby
- 1Australian Centre for Microscopy and Microanalysis,The University of Sydney,Sydney,NSW 2006,Australia
| | - Sophie Primig
- 4School of Materials Science and Engineering,The University of New South Wales,Sydney,NSW 2052,Australia
| | - Julie M Cairney
- 1Australian Centre for Microscopy and Microanalysis,The University of Sydney,Sydney,NSW 2006,Australia
| | - Simon P Ringer
- 1Australian Centre for Microscopy and Microanalysis,The University of Sydney,Sydney,NSW 2006,Australia
| |
Collapse
|
43
|
Chen Z, Hong L, Wang F, Ringer SP, Chen LQ, Luo H, Liao X. Facilitation of Ferroelectric Switching via Mechanical Manipulation of Hierarchical Nanoscale Domain Structures. Phys Rev Lett 2017; 118:017601. [PMID: 28106439 DOI: 10.1103/physrevlett.118.017601] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/14/2016] [Indexed: 06/06/2023]
Abstract
Heterogeneous ferroelastic transition that produces hierarchical 90° tetragonal nanodomains via mechanical loading and its effect on facilitating ferroelectric domain switching in relaxor-based ferroelectrics were explored. Combining in situ electron microscopy characterization and phase-field modeling, we reveal the nature of the transition process and discover that the transition lowers by 40% the electrical loading threshold needed for ferroelectric domain switching. Our results advance the fundamental understanding of ferroelectric domain switching behavior.
Collapse
Affiliation(s)
- Zibin Chen
- School of Aerospace, Mechanical and Mechatronic Engineering, The University of Sydney, Sydney, New South Wales 2006, Australia
| | - Liang Hong
- Department of Materials Science and Engineering, Pennsylvania State University, University Park, Pennsylvania 16802, USA
| | - Feifei Wang
- Key Laboratory of Optoelectronic Material and Device, Department of Physics, Shanghai Normal University, Shanghai 200234, China
| | - Simon P Ringer
- School of Aerospace, Mechanical and Mechatronic Engineering, The University of Sydney, Sydney, New South Wales 2006, Australia
- Australian Institute for Nanoscale Science and Technology, The University of Sydney, New South Wales 2006, Australia
| | - Long-Qing Chen
- Department of Materials Science and Engineering, Pennsylvania State University, University Park, Pennsylvania 16802, USA
| | - Haosu Luo
- Key Laboratory of Inorganic Functional Materials and Devices, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050, China
| | - Xiaozhou Liao
- School of Aerospace, Mechanical and Mechatronic Engineering, The University of Sydney, Sydney, New South Wales 2006, Australia
| |
Collapse
|
44
|
Saadaoui H, Luo X, Salman Z, Cui XY, Bao NN, Bao P, Zheng RK, Tseng LT, Du YH, Prokscha T, Suter A, Liu T, Wang YR, Li S, Ding J, Ringer SP, Morenzoni E, Yi JB. Intrinsic Ferromagnetism in the Diluted Magnetic Semiconductor Co:TiO_{2}. Phys Rev Lett 2016; 117:227202. [PMID: 27925730 DOI: 10.1103/physrevlett.117.227202] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2016] [Indexed: 06/06/2023]
Abstract
Here we present a study of magnetism in Co_{0.05}Ti_{0.95}O_{2-δ} anatase films grown by pulsed laser deposition under a variety of oxygen partial pressures and deposition rates. Energy-dispersive spectrometry and transmission electron microscopy analyses indicate that a high deposition rate leads to a homogeneous microstructure, while a very low rate or postannealing results in cobalt clustering. Depth resolved low-energy muon spin rotation experiments show that films grown at a low oxygen partial pressure (≈10^{-6} torr) with a uniform structure are fully magnetic, indicating intrinsic ferromagnetism. First principles calculations identify the beneficial role of low oxygen partial pressure in the realization of uniform carrier-mediated ferromagnetism. This work demonstrates that Co:TiO_{2} is an intrinsic diluted magnetic semiconductor.
Collapse
Affiliation(s)
- H Saadaoui
- Laboratory for Muon Spin Spectroscopy, Paul Scherrer Institute, 5232 Villigen PSI, Switzerland
| | - X Luo
- School of Materials Science and Engineering, UNSW, Sydney, New South Wales 2052, Australia
| | - Z Salman
- Laboratory for Muon Spin Spectroscopy, Paul Scherrer Institute, 5232 Villigen PSI, Switzerland
| | - X Y Cui
- School of Aerospace, Mechanical and Mechatronic Engineering, The University of Sydney, Sydney, New South Wales 2006, Australia
| | - N N Bao
- Department of Materials Science and Engineering, National University of Singapore, 119260, Singapore
| | - P Bao
- School of Physics, The University of Sydney, Sydney, New South Wales 2006, Australia
| | - R K Zheng
- School of Physics, The University of Sydney, Sydney, New South Wales 2006, Australia
| | - L T Tseng
- School of Materials Science and Engineering, UNSW, Sydney, New South Wales 2052, Australia
| | - Y H Du
- Institute of Chemical and Engineering Science, Agency for Science, Technology and Research (A*STAR), 1 Pesek Road, Jurong Island, 627833, Singapore
| | - T Prokscha
- Laboratory for Muon Spin Spectroscopy, Paul Scherrer Institute, 5232 Villigen PSI, Switzerland
| | - A Suter
- Laboratory for Muon Spin Spectroscopy, Paul Scherrer Institute, 5232 Villigen PSI, Switzerland
| | - T Liu
- ANKA, Karlsruhe Institute of Technology, 76344 Eggenstein-Leopoldshafen, Germany
| | - Y R Wang
- School of Materials Science and Engineering, UNSW, Sydney, New South Wales 2052, Australia
| | - S Li
- School of Materials Science and Engineering, UNSW, Sydney, New South Wales 2052, Australia
| | - J Ding
- Department of Materials Science and Engineering, National University of Singapore, 119260, Singapore
| | - S P Ringer
- School of Aerospace, Mechanical and Mechatronic Engineering, The University of Sydney, Sydney, New South Wales 2006, Australia
- The Australian Institute for Nanoscale Science and Technology, The University of Sydney, Sydney, New South Wales 2006, Australia
| | - E Morenzoni
- Laboratory for Muon Spin Spectroscopy, Paul Scherrer Institute, 5232 Villigen PSI, Switzerland
| | - J B Yi
- School of Materials Science and Engineering, UNSW, Sydney, New South Wales 2052, Australia
| |
Collapse
|
45
|
Abstract
Findings of laser-assisted atom probe tomography experiments on boron carbide elucidate an approach for characterizing the atomic structure and interatomic bonding of molecules associated with extraordinary structural stability. The discovery of crystallographic planes in these boron carbide datasets substantiates that crystallinity is maintained to the point of field evaporation, and characterization of individual ionization events gives unexpected evidence of the destruction of individual icosahedra. Statistical analyses of the ions created during the field evaporation process have been used to deduce relative atomic bond strengths and show that the icosahedra in boron carbide are not as stable as anticipated. Combined with quantum mechanics simulations, this result provides insight into the structural instability and amorphization of boron carbide. The temporal, spatial, and compositional information provided by atom probe tomography makes it a unique platform for elucidating the relative stability and interactions of primary building blocks in hierarchically crystalline materials.
Collapse
Affiliation(s)
- Kelvin Y Xie
- Department of Mechanical Engineering, Johns Hopkins University, Baltimore, MD 21218
| | - Qi An
- Materials and Process Simulation Center, California Institute of Technology, Pasadena, CA 91125
| | - Takanori Sato
- Australian Centre for Microscopy and Microanalysis, The University of Sydney, Sydney, NSW 2006, Australia
| | - Andrew J Breen
- Australian Centre for Microscopy and Microanalysis, The University of Sydney, Sydney, NSW 2006, Australia; School of Aerospace, Mechanical and Mechatronic Engineering, The University of Sydney, Sydney, NSW 2006, Australia
| | - Simon P Ringer
- Australian Centre for Microscopy and Microanalysis, The University of Sydney, Sydney, NSW 2006, Australia; Australian Institute for Nanoscale Science and Technology, The University of Sydney, Sydney, NSW 2006, Australia
| | - William A Goddard
- Materials and Process Simulation Center, California Institute of Technology, Pasadena, CA 91125
| | - Julie M Cairney
- Australian Centre for Microscopy and Microanalysis, The University of Sydney, Sydney, NSW 2006, Australia; School of Aerospace, Mechanical and Mechatronic Engineering, The University of Sydney, Sydney, NSW 2006, Australia
| | - Kevin J Hemker
- Department of Mechanical Engineering, Johns Hopkins University, Baltimore, MD 21218; Department of Materials Science and Engineering, Johns Hopkins University, Baltimore, MD 21218
| |
Collapse
|
46
|
Chen Z, Wang X, Ringer SP, Liao X. Manipulation of Nanoscale Domain Switching Using an Electron Beam with Omnidirectional Electric Field Distribution. Phys Rev Lett 2016; 117:027601. [PMID: 27447524 DOI: 10.1103/physrevlett.117.027601] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/06/2015] [Indexed: 06/06/2023]
Abstract
Reversible ferroelectric domain (FD) manipulation with a high spatial resolution is critical for memory storage devices based on thin film ferroelectric materials. FD can be manipulated using techniques that apply heat, mechanical stress, or electric bias. However, these techniques have some drawbacks. Here we propose to use an electron beam with an omnidirectional electric field as a tool for erasable stable ferroelectric nanodomain manipulation. Our results suggest that local accumulation of charges contributes to the local electric field that determines domain configurations.
Collapse
Affiliation(s)
- Zibin Chen
- School of Aerospace, Mechanical and Mechatronic Engineering, The University of Sydney, Sydney, New South Wales 2006, Australia
| | - Xiaolin Wang
- Institute for Superconducting and Electronic Materials, Faculty of Engineering, Australian Institute for Innovative Materials, University of Wollongong, Wollongong, New South Wales 2522, Australia
| | - Simon P Ringer
- School of Aerospace, Mechanical and Mechatronic Engineering, The University of Sydney, Sydney, New South Wales 2006, Australia
- Australian Institute for Nanoscale Science and Technology, The University of Sydney, Sydney, New South Wales 2006, Australia
| | - Xiaozhou Liao
- School of Aerospace, Mechanical and Mechatronic Engineering, The University of Sydney, Sydney, New South Wales 2006, Australia
| |
Collapse
|
47
|
Abstract
Through first-principles calculations using the nonequilibrium Green's function formalism together with density functional theory, we study the conductance of double-vacancy zigzag graphene nanoribbons doped with four transition metal atoms Ti, V, Cr and Fe. We show that Ti doping induces large spin-filtering with an efficiency in excess of 90% for bias voltages below 0.5 V, while the other metal adatoms do not induce large spin filtering. This is despite the fact that the Ti dopant possesses small spin moment, while large moments reside on V, Cr and Fe dopants. Our analysis shows that the suppression of transmission in the spin-down channel in the Ti-doped graphene nanoribbon, thus the large spin filtering efficiency, is due to transmission anti-resonance arising from destructive quantum interference. These findings suggest that the decoration of graphene with titanium, and possibly other transition metals, can act as effective spin filters for nanospintronic applications.
Collapse
|
48
|
Chen Y, Burgess T, An X, Mai YW, Tan HH, Zou J, Ringer SP, Jagadish C, Liao X. Effect of a High Density of Stacking Faults on the Young's Modulus of GaAs Nanowires. Nano Lett 2016; 16:1911-1916. [PMID: 26885570 DOI: 10.1021/acs.nanolett.5b05095] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Stacking faults (SFs) are commonly observed crystalline defects in III-V semiconductor nanowires (NWs) that affect a variety of physical properties. Understanding the effect of SFs on NW mechanical properties is critical to NW applications in nanodevices. In this study, the Young's moduli of GaAs NWs with two distinct structures, defect-free single crystalline wurtzite (WZ) and highly defective wurtzite containing a high density of SFs (WZ-SF), are investigated using combined in situ compression transmission electron microscopy and finite element analysis. The Young's moduli of both WZ and WZ-SF GaAs NWs were found to increase with decreasing diameter due to the increasing volume fraction of the native oxide shell. The presence of a high density of SFs was further found to increase the Young's modulus by 13%. This stiffening effect of SFs is attributed to the change in the interatomic bonding configuration at the SFs.
Collapse
Affiliation(s)
| | - Tim Burgess
- Department of Electronic Materials Engineering, Research School of Physics and Engineering, The Australian National University , Canberra, Australian Capital Territory 2601, Australia
| | | | | | - H Hoe Tan
- Department of Electronic Materials Engineering, Research School of Physics and Engineering, The Australian National University , Canberra, Australian Capital Territory 2601, Australia
| | - Jin Zou
- Materials Engineering and Centre for Microscopy and Microanalysis, The University of Queensland , St. Lucia, Queensland 4072, Australia
| | | | - Chennupati Jagadish
- Department of Electronic Materials Engineering, Research School of Physics and Engineering, The Australian National University , Canberra, Australian Capital Territory 2601, Australia
| | | |
Collapse
|
49
|
Tawfik SA, Cui XY, Ringer SP, Stampfl C. Enhanced oscillatory rectification and negative differential resistance in pentamantane diamondoid-cumulene systems. Nanoscale 2016; 8:3461-3466. [PMID: 26794415 DOI: 10.1039/c5nr07467c] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
We propose a new functionality for diamondoids in nanoelectronics. Based on the nonequilibrium Green's function formalism and density functional theory, we reveal that when attached to gold electrodes, the pentamantane-cumulene molecular junction exhibits large and oscillatory rectification and negative differential resistance (NDR) - depending on the number of carbon atoms in cumulene (Cn). When n is odd rectification is greatly enhanced where the rectification ratio can reach ∼180 and a large negative differential resistance peak current of ∼3 μA. This oscillatory behavior is well rationalised in terms of the occupancy of the carbon 2p states in Cn. Interestingly, different layers of C atoms in the pentamantane molecule have different contributions to transmission. The first and third layers of C atoms in pentamantane have a slight contribution to rectification, and the fifth and sixth layers have a stronger contribution to both rectification and NDR. Thus, our results suggest potential avenues for controlling their functions by chemically manipulating various parts of the diamondoid molecule, thus extending the applications of diamondoids in nanoscale integrated circuits.
Collapse
|
50
|
Tawfik SA, Cui XY, Ringer SP, Stampfl C. Communication: Electrical rectification of C59N: The role of anchoring and doping sites. J Chem Phys 2016; 144:021101. [PMID: 26772547 DOI: 10.1063/1.4940142] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Based on the nonequilibrium Green's function formalism and density-functional theory, we investigate the onset of electrical rectification in a single C59N molecule in conjunction with gold electrodes. Our calculations reveal that rectification is dependent upon the anchoring of the Au atom on C59N; when the Au electrode is singly bonded to a C atom (labeled here as A), the system does not exhibit rectification, whereas when the electrode is connected to the C-C bridge site between two hexagonal rings (labeled here as B), transmission asymmetry is observed, where the rectification ratio reaches up to 2.62 at ±1 V depending on the N doping site relative to the anchoring site. Our analysis of the transmission mechanism shows that N doping of the B configuration causes rectification because more transmission channels are available for transmission in the B configuration than in the A configuration.
Collapse
Affiliation(s)
| | - X Y Cui
- Australian Centre for Microscopy and Microanalysis, and School of Aerospace, Mechanical and Mechatronic Engineering, The University of Sydney, Sydney, New South Wales 2006, Australia
| | - S P Ringer
- Australian Centre for Microscopy and Microanalysis, and School of Aerospace, Mechanical and Mechatronic Engineering, The University of Sydney, Sydney, New South Wales 2006, Australia
| | - C Stampfl
- School of Physics, The University of Sydney, Sydney, New South Wales 2006, Australia
| |
Collapse
|