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Guo J, He B, Han Y, Liu H, Han J, Ma X, Wang J, Gao W, Lü W. Resurrected and Tunable Conductivity and Ferromagnetism in the Secondary Growth La 0.7Ca 0.3MnO 3 on Transferred SrTiO 3 Membranes. NANO LETTERS 2024; 24:1114-1121. [PMID: 38252877 DOI: 10.1021/acs.nanolett.3c03651] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2024]
Abstract
To avoid the epitaxy dilemma in various thin films, such as complex oxide, silicon, organic, metal/alloy, etc., their stacking at an atomic level and secondary growth are highly desired to maximize the functionality of a promising electronic device. The ceramic nature of complex oxides and the demand for accurate and long-range-ordered stoichiometry face severe challenges. Here, the transport and magnetic properties of the La0.7Ca0.3MnO3 (LCMO) secondary growth on single-crystal freestanding SrTiO3 (STO) membranes are demonstrated. It has been experimentally found that on an only 10 nm thick STO membrane, the LCMO can offer a bulk-like Curie temperature (TC) of 253 K and negative magnetoresistance of -64%, with a weak dependence on the thickness. The resurrected conductivity and ferromagnetism in LCMO confirm the advantages of secondary growth, which benefits from the excellent flexibility and transferability. Additionally, this study explores the integration strategy of complex oxides with other functional materials.
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Affiliation(s)
- Jinrui Guo
- Spintronics Institute, School of Physics and Technology, University of Jinan, Jinan 250022, China
| | - Bin He
- Spintronics Institute, School of Physics and Technology, University of Jinan, Jinan 250022, China
| | - Yue Han
- Country Functional Materials and Acousto-Optic Instruments Institute, School of Instrumentation Science and Engineering, Harbin Institute of Technology, Harbin 150080, China
| | - Huan Liu
- Country Functional Materials and Acousto-Optic Instruments Institute, School of Instrumentation Science and Engineering, Harbin Institute of Technology, Harbin 150080, China
| | - Jiale Han
- Spintronics Institute, School of Physics and Technology, University of Jinan, Jinan 250022, China
| | - Xiaoqiao Ma
- Spintronics Institute, School of Physics and Technology, University of Jinan, Jinan 250022, China
| | - Jiaqing Wang
- Spintronics Institute, School of Physics and Technology, University of Jinan, Jinan 250022, China
| | - Wenqi Gao
- Spintronics Institute, School of Physics and Technology, University of Jinan, Jinan 250022, China
| | - Weiming Lü
- Spintronics Institute, School of Physics and Technology, University of Jinan, Jinan 250022, China
- Country Functional Materials and Acousto-Optic Instruments Institute, School of Instrumentation Science and Engineering, Harbin Institute of Technology, Harbin 150080, China
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2
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Ziatdinov M, Ghosh A, Wong CY, Kalinin SV. AtomAI framework for deep learning analysis of image and spectroscopy data in electron and scanning probe microscopy. NAT MACH INTELL 2022. [DOI: 10.1038/s42256-022-00555-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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3
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Agyeman DA, Zheng Y, Lee TH, Park M, Tamakloe W, Lee GH, Jang HW, Cho K, Kang YM. Synergistic Catalysis of the Lattice Oxygen and Transition Metal Facilitating ORR and OER in Perovskite Catalysts for Li–O2 Batteries. ACS Catal 2020. [DOI: 10.1021/acscatal.0c02608] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Daniel Adjei Agyeman
- Department of Energy and Materials Engineering, Dongguk University-Seoul, Seoul 04620, Republic of Korea
| | - Yongping Zheng
- Department of Materials Science and Engineering, University of Texas at Dallas, Richardson, Texas 75080, United States
- Functional Thin Films Research Center, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China
| | - Tae-Hyeong Lee
- Department of Materials Science and Engineering, Research Institute for Advanced Materials, Seoul National University, Seoul 08826, Republic of Korea
| | - Mihui Park
- Department of Energy and Materials Engineering, Dongguk University-Seoul, Seoul 04620, Republic of Korea
| | - Wilson Tamakloe
- Department of Energy and Materials Engineering, Dongguk University-Seoul, Seoul 04620, Republic of Korea
| | - Gi-Hyeok Lee
- Department of Energy and Materials Engineering, Dongguk University-Seoul, Seoul 04620, Republic of Korea
| | - Ho Won Jang
- Department of Materials Science and Engineering, Research Institute for Advanced Materials, Seoul National University, Seoul 08826, Republic of Korea
| | - Kyeongjae Cho
- Department of Materials Science and Engineering, University of Texas at Dallas, Richardson, Texas 75080, United States
| | - Yong-Mook Kang
- Department of Materials Science and Engineering, Korea University, Seoul 02841, Republic of Korea
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4
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Depth-Resolved Phase Analysis of Expanded Austenite Formed in Austenitic Stainless Steel. COATINGS 2020. [DOI: 10.3390/coatings10121250] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Expanded austenite γN formed after nitrogen insertion into austenitic stainless steel and CoCr alloys is known as a hard and very wear resistant phase. Nevertheless, no single composition and lattice expansion can describe this phase with nitrogen in solid solution. Using in situ X-ray diffraction (XRD) during ion beam sputtering of expanded austenite allows a detailed depth-dependent phase analysis, correlated with the nitrogen depth profiles obtained by time-of-flight secondary ion mass spectrometry (ToF-SIMS) or glow discharge optical emission spectroscopy (GDOES). Additionally, in-plane XRD measurements at selected depths were performed for strain analysis. Surprisingly, an anomalous peak splitting for the (200) expanded peak was observed for some samples during nitriding and sputter etching, indicating a layered structure only for {200} oriented grains. The strain analysis as a function of depth and orientation of scattering vector (parallel/perpendicular to the surface) is inconclusive.
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5
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Sha H, Liang S, Liu L, Cheng Z, Zhu J, Yu R. Surface termination and stoichiometry of LaAlO 3(001) surface studied by HRTEM. Micron 2020; 137:102919. [PMID: 32763838 DOI: 10.1016/j.micron.2020.102919] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2020] [Revised: 07/17/2020] [Accepted: 07/17/2020] [Indexed: 10/23/2022]
Abstract
As an important topic of condensed matter physics, metal oxide surfaces often exhibit exotic properties such as high catalytic activity, enhanced ferroelectricity and electronic phase transition, originating from the different local symmetry with respect to the bulk. As the structure determination of oxide surfaces presents challenges to conventional surface science techniques like scanning tunneling microscopy, aberration-corrected transmission electron microscopy (TEM) has been increasingly used to solve structures of oxide surfaces. In this work, the (001) surface of LaAlO3, one of the most used components of oxide heterostructures, has been investigated. Our TEM experiments and extensive image simulations show that the La-O terminated LaAlO3(001) surface undergoes significant reconstructions, forming La vacancies on the surface layer. Energetically, the LaAlO3(001) surface is stable with the reconstructed La-O termination in a wide range of oxygen chemical potentials. Polarity compensation, reduced density of states at the Fermi level and bond enhancement of subsurface oxygen anions all contribute to the stabilization of the reconstructed surface.
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Affiliation(s)
- Haozhi Sha
- National Center for Electron Microscopy in Beijing, Key Laboratory of Advanced Materials of Ministry of Education of China, State Key Laboratory of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing, 100084, China
| | - Shiyou Liang
- National Center for Electron Microscopy in Beijing, Key Laboratory of Advanced Materials of Ministry of Education of China, State Key Laboratory of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing, 100084, China
| | - Linhan Liu
- National Center for Electron Microscopy in Beijing, Key Laboratory of Advanced Materials of Ministry of Education of China, State Key Laboratory of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing, 100084, China
| | - Zhiying Cheng
- National Center for Electron Microscopy in Beijing, Key Laboratory of Advanced Materials of Ministry of Education of China, State Key Laboratory of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing, 100084, China
| | - Jing Zhu
- National Center for Electron Microscopy in Beijing, Key Laboratory of Advanced Materials of Ministry of Education of China, State Key Laboratory of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing, 100084, China
| | - Rong Yu
- National Center for Electron Microscopy in Beijing, Key Laboratory of Advanced Materials of Ministry of Education of China, State Key Laboratory of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing, 100084, China.
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6
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Gudkov VV, Sarychev MN, Zherlitsyn S, Zhevstovskikh IV, Averkiev NS, Vinnik DA, Gudkova SA, Niewa R, Dressel M, Alyabyeva LN, Gorshunov BP, Bersuker IB. Sub-lattice of Jahn-Teller centers in hexaferrite crystal. Sci Rep 2020; 10:7076. [PMID: 32341430 PMCID: PMC7184747 DOI: 10.1038/s41598-020-63915-7] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2019] [Accepted: 04/01/2020] [Indexed: 11/09/2022] Open
Abstract
A novel type of sub-lattice of the Jahn-Teller (JT) centers was arranged in Ti-doped barium hexaferrite BaFe12O19. In the un-doped crystal all iron ions, sitting in five different crystallographic positions, are Fe3+ in the high-spin configuration (S = 5/2) and have a non-degenerate ground state. We show that the electron-donor Ti substitution converts the ions to Fe2+ predominantly in tetrahedral coordination, resulting in doubly-degenerate states subject to the [Formula: see text] problem of the JT effect. The arranged JT complexes, Fe2+O4, their adiabatic potential energy, non-linear and quantum dynamics, have been studied by means of ultrasound and terahertz-infrared spectroscopies. The JT complexes are sensitive to external stress and applied magnetic field. For that reason, the properties of the doped crystal can be controlled by the amount and state of the JT complexes.
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Affiliation(s)
- V V Gudkov
- Institute of Physics and Technology, Ural Federal University, Ekaterinburg, Russia.,South Ural State University, Chelyabinsk, Russia
| | - M N Sarychev
- Institute of Physics and Technology, Ural Federal University, Ekaterinburg, Russia
| | - S Zherlitsyn
- Hochfeld-Magnetlabor Dresden (HLD-EMFL), Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany
| | - I V Zhevstovskikh
- Institute of Physics and Technology, Ural Federal University, Ekaterinburg, Russia.,M.N. Miheev Institute of Metal Physics, UB of the RAS, Ekaterinburg, Russia
| | - N S Averkiev
- A.F. Ioffe Physical Technical Institute of the RAS, St. Petersburg, Russia
| | - D A Vinnik
- South Ural State University, Chelyabinsk, Russia
| | - S A Gudkova
- South Ural State University, Chelyabinsk, Russia.,Moscow Institute of Physics and Technology (State University), Dolgoprudny, Russia
| | - R Niewa
- Institute of Inorganic Chemistry, University of Stuttgart, Stuttgart, Germany
| | - M Dressel
- Moscow Institute of Physics and Technology (State University), Dolgoprudny, Russia.,1. Physikalisches Institut, Universität Stuttgart, Stuttgart, Germany
| | - L N Alyabyeva
- Moscow Institute of Physics and Technology (State University), Dolgoprudny, Russia.
| | - B P Gorshunov
- Moscow Institute of Physics and Technology (State University), Dolgoprudny, Russia
| | - I B Bersuker
- Institute for Theoretical Chemistry, the University of Texas at Austin, Austin, TX, USA
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7
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Vlcek L, Ziatdinov M, Maksov A, Tselev A, Baddorf AP, Kalinin SV, Vasudevan RK. Learning from Imperfections: Predicting Structure and Thermodynamics from Atomic Imaging of Fluctuations. ACS NANO 2019; 13:718-727. [PMID: 30609895 DOI: 10.1021/acsnano.8b07980] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
In materials characterization, traditionally a single experimental sample is used to derive information about a single point in the composition space, while the imperfections, impurities, and stochastic details of material structure are deemed irrelevant or complicating factors in the analysis. Here we demonstrate that atomic-scale studies of a single nominal composition can provide information about microstructures and thermodynamic response over a finite area of chemical space. Using the principles of statistical inference, we develop a framework for incorporating structural fluctuations into statistical mechanical models and use it to solve the inverse problem of deriving effective interatomic interactions responsible for elemental segregation in a La5/8Ca3/8MnO3 thin film. The results are further analyzed by a variational autoencoder to detect anomalous behavior in the composition phase diagram. This study provides a framework for creating generative models from a combination of multiple experimental data and provides direct insight into the driving forces for cation segregation in manganites.
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Affiliation(s)
- Lukas Vlcek
- Joint Institute for Computational Sciences , University of Tennessee , Knoxville , Tennessee 37996 , United States
| | | | - Artem Maksov
- UT Bredesen Center for Interdisciplinary Research , University of Tennessee , Knoxville , Tennessee 37996 , United States
| | - Alexander Tselev
- Department of Physics , CICECO - Aveiro Institute of Materials , 3810-193 Aveiro , Portugal
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8
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Somnath S, Smith CR, Kalinin SV, Chi M, Borisevich A, Cross N, Duscher G, Jesse S. Feature extraction via similarity search: application to atom finding and denoising in electron and scanning probe microscopy imaging. ADVANCED STRUCTURAL AND CHEMICAL IMAGING 2018; 4:3. [PMID: 29568723 PMCID: PMC5846807 DOI: 10.1186/s40679-018-0052-y] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/04/2017] [Accepted: 01/27/2018] [Indexed: 11/10/2022]
Abstract
We develop an algorithm for feature extraction based on structural similarity and demonstrate its application for atom and pattern finding in high-resolution electron and scanning probe microscopy images. The use of the combined local identifiers formed from an image subset and appended Fourier, or other transform, allows tuning selectivity to specific patterns based on the nature of the recognition task. The proposed algorithm is implemented in Pycroscopy, a community-driven scientific data analysis package, and is accessible through an interactive Jupyter notebook available on GitHub.
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Affiliation(s)
- Suhas Somnath
- The Institute for Functional Imaging of Materials, Oak Ridge National Laboratory, Oak Ridge, TN 37801 USA
- The Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN 37801 USA
| | - Christopher R. Smith
- The Institute for Functional Imaging of Materials, Oak Ridge National Laboratory, Oak Ridge, TN 37801 USA
- The Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN 37801 USA
| | - Sergei V. Kalinin
- The Institute for Functional Imaging of Materials, Oak Ridge National Laboratory, Oak Ridge, TN 37801 USA
- The Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN 37801 USA
| | - Miaofang Chi
- The Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN 37801 USA
| | - Albina Borisevich
- The Institute for Functional Imaging of Materials, Oak Ridge National Laboratory, Oak Ridge, TN 37801 USA
- Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN 37801 USA
| | - Nicholas Cross
- Department of Materials Science and Engineering, University of Tennessee, Knoxville, TN 37996 USA
| | - Gerd Duscher
- Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN 37801 USA
- Department of Materials Science and Engineering, University of Tennessee, Knoxville, TN 37996 USA
| | - Stephen Jesse
- The Institute for Functional Imaging of Materials, Oak Ridge National Laboratory, Oak Ridge, TN 37801 USA
- The Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN 37801 USA
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9
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Okada Y, Shiau SY, Chang TR, Chang G, Kobayashi M, Shimizu R, Jeng HT, Shiraki S, Kumigashira H, Bansil A, Lin H, Hitosugi T. Quasiparticle Interference on Cubic Perovskite Oxide Surfaces. PHYSICAL REVIEW LETTERS 2017; 119:086801. [PMID: 28952762 DOI: 10.1103/physrevlett.119.086801] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/25/2016] [Indexed: 06/07/2023]
Abstract
We report the observation of coherent surface states on cubic perovskite oxide SrVO_{3}(001) thin films through spectroscopic-imaging scanning tunneling microscopy. A direct link between the observed quasiparticle interference patterns and the formation of a d_{xy}-derived surface state is supported by first-principles calculations. We show that the apical oxygens on the topmost VO_{2} plane play a critical role in controlling the coherent surface state via modulating orbital state.
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Affiliation(s)
- Yoshinori Okada
- Advanced Institute for Materials Research (AIMR), Tohoku University, Sendai 980-8577, Japan
| | - Shiue-Yuan Shiau
- Centre for Advanced 2D Materials and Graphene Research Centre, National University of Singapore, Singapore 117546, Singapore
- Department of Physics, National University of Singapore, Singapore 117542, Singapore
| | - Tay-Rong Chang
- Department of Physics, National Tsing Hua University, Hsinchu 30013, Taiwan
- Department of Physics, National Cheng Kung University, Tainan 701, Taiwan
| | - Guoqing Chang
- Centre for Advanced 2D Materials and Graphene Research Centre, National University of Singapore, Singapore 117546, Singapore
- Department of Physics, National University of Singapore, Singapore 117542, Singapore
| | - Masaki Kobayashi
- Photon Factory, Institute of Materials Structure Science, High Energy Accelerator Research Organization (KEK), 1-1 Oho, Tsukuba 305-0801, Japan
| | - Ryota Shimizu
- Advanced Institute for Materials Research (AIMR), Tohoku University, Sendai 980-8577, Japan
| | - Horng-Tay Jeng
- Department of Physics, National Tsing Hua University, Hsinchu 30013, Taiwan
- Institute of Physics, Academia Sinica, Taipei 11529, Taiwan
| | - Susumu Shiraki
- Advanced Institute for Materials Research (AIMR), Tohoku University, Sendai 980-8577, Japan
| | - Hiroshi Kumigashira
- Photon Factory, Institute of Materials Structure Science, High Energy Accelerator Research Organization (KEK), 1-1 Oho, Tsukuba 305-0801, Japan
| | - Arun Bansil
- Department of Physics, Northeastern University, Boston, Massachusetts 02115, USA
| | - Hsin Lin
- Centre for Advanced 2D Materials and Graphene Research Centre, National University of Singapore, Singapore 117546, Singapore
- Department of Physics, National University of Singapore, Singapore 117542, Singapore
| | - Taro Hitosugi
- Advanced Institute for Materials Research (AIMR), Tohoku University, Sendai 980-8577, Japan
- Department of Applied Chemistry, Tokyo Institute of Technology, Tokyo 152-8552, Japan
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10
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Zou Q, Wu Z, Fu M, Zhang C, Rajput S, Wu Y, Li L, Parker DS, Kang J, Sefat AS, Gai Z. Effect of Surface Morphology and Magnetic Impurities on the Electronic Structure in Cobalt-Doped BaFe 2As 2 Superconductors. NANO LETTERS 2017; 17:1642-1647. [PMID: 28140593 DOI: 10.1021/acs.nanolett.6b04825] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Combined scanning tunneling microscopy, spectroscopy, and local barrier height (LBH) studies show that low-temperature-cleaved optimally doped Ba(Fe1-xCox)2As2 crystals with x = 0.06, with Tc = 22 K, have complicated morphologies. Although the cleavage surface and hence the morphologies are variable, the superconducting gap maps show the same gap widths and nanometer size inhomogeneities irrelevant to the morphology. Based on the spectroscopy and LBH maps, the bright patches and dark stripes in the morphologies are identified as Ba- and As-dominated surface terminations, respectively. Magnetic impurities, possibly due to Co or Fe atoms, are believed to create local in-gap state and, in addition, suppress the superconducting coherence peaks. This study will clarify the confusion on the cleavage surface terminations of the Fe-based superconductors and its relation with the electronic structures.
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Affiliation(s)
- Qiang Zou
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory , Oak Ridge, Tennessee 37831, United States
| | - Zhiming Wu
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory , Oak Ridge, Tennessee 37831, United States
- Fujian Provincial Key Laboratory of Semiconductors and Applications, Collaborative Innovation Center for Optoelectronic Semiconductors and Efficient Devices, Department of Physics, Xiamen University , Xiamen, Fujian Province 361005, P. R. China
| | - Mingming Fu
- Fujian Provincial Key Laboratory of Semiconductors and Applications, Collaborative Innovation Center for Optoelectronic Semiconductors and Efficient Devices, Department of Physics, Xiamen University , Xiamen, Fujian Province 361005, P. R. China
| | - Chunmiao Zhang
- Fujian Provincial Key Laboratory of Semiconductors and Applications, Collaborative Innovation Center for Optoelectronic Semiconductors and Efficient Devices, Department of Physics, Xiamen University , Xiamen, Fujian Province 361005, P. R. China
| | - S Rajput
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory , Oak Ridge, Tennessee 37831, United States
- Materials Science & Technology Division, Oak Ridge National Laboratory , Oak Ridge, Tennessee 37831, United States
| | - Yaping Wu
- Fujian Provincial Key Laboratory of Semiconductors and Applications, Collaborative Innovation Center for Optoelectronic Semiconductors and Efficient Devices, Department of Physics, Xiamen University , Xiamen, Fujian Province 361005, P. R. China
| | - Li Li
- Materials Science & Technology Division, Oak Ridge National Laboratory , Oak Ridge, Tennessee 37831, United States
| | - D S Parker
- Materials Science & Technology Division, Oak Ridge National Laboratory , Oak Ridge, Tennessee 37831, United States
| | - Junyong Kang
- Fujian Provincial Key Laboratory of Semiconductors and Applications, Collaborative Innovation Center for Optoelectronic Semiconductors and Efficient Devices, Department of Physics, Xiamen University , Xiamen, Fujian Province 361005, P. R. China
| | - A S Sefat
- Materials Science & Technology Division, Oak Ridge National Laboratory , Oak Ridge, Tennessee 37831, United States
| | - Zheng Gai
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory , Oak Ridge, Tennessee 37831, United States
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11
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Ly TT, Duvjir G, Min T, Byun J, Kim T, Saad MM, Hai NTM, Cho S, Lee J, Kim J. Atomistic study of the alloying behavior of crystalline SnSe1−xSx. Phys Chem Chem Phys 2017; 19:21648-21654. [DOI: 10.1039/c7cp03481d] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The alloying behavior of crystalline SnSe1−xSx was investigated at the atomic level by combining STM experiments and DFT calculations.
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12
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Identifying local structural states in atomic imaging by computer vision. ACTA ACUST UNITED AC 2016; 2:14. [PMID: 27867837 PMCID: PMC5093204 DOI: 10.1186/s40679-016-0028-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2016] [Accepted: 10/26/2016] [Indexed: 11/10/2022]
Abstract
The availability of atomically resolved imaging modalities enables an unprecedented view into the local structural states of materials, which manifest themselves by deviations from the fundamental assumptions of periodicity and symmetry. Consequently, approaches that aim to extract these local structural states from atomic imaging data with minimal assumptions regarding the average crystallographic configuration of a material are indispensable to advances in structural and chemical investigations of materials. Here, we present an approach to identify and classify local structural states that is rooted in computer vision. This approach introduces a definition of a structural state that is composed of both local and nonlocal information extracted from atomically resolved images, and is wholly untethered from the familiar concepts of symmetry and periodicity. Instead, this approach relies on computer vision techniques such as feature detection, and concepts such as scale invariance. We present the fundamental aspects of local structural state extraction and classification by application to simulated scanning transmission electron microscopy images, and analyze the robustness of this approach in the presence of common instrumental factors such as noise, limited spatial resolution, and weak contrast. Finally, we apply this computer vision-based approach for the unsupervised detection and classification of local structural states in an experimental electron micrograph of a complex oxides interface, and a scanning tunneling micrograph of a defect-engineered multilayer graphene surface.
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13
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Identification of phases, symmetries and defects through local crystallography. Nat Commun 2015; 6:7801. [PMID: 26190623 PMCID: PMC4518243 DOI: 10.1038/ncomms8801] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2014] [Accepted: 06/11/2015] [Indexed: 01/28/2023] Open
Abstract
Advances in electron and probe microscopies allow 10 pm or higher precision in measurements of atomic positions. This level of fidelity is sufficient to correlate the length (and hence energy) of bonds, as well as bond angles to functional properties of materials. Traditionally, this relied on mapping locally measured parameters to macroscopic variables, for example, average unit cell. This description effectively ignores the information contained in the microscopic degrees of freedom available in a high-resolution image. Here we introduce an approach for local analysis of material structure based on statistical analysis of individual atomic neighbourhoods. Clustering and multivariate algorithms such as principal component analysis explore the connectivity of lattice and bond structure, as well as identify minute structural distortions, thus allowing for chemical description and identification of phases. This analysis lays the framework for building image genomes and structure–property libraries, based on conjoining structural and spectral realms through local atomic behaviour. High-resolution microscopy methods provide a rich source of information, and allow highly precise measurements of atomic coordinates. Here, the authors report a method for quantitative analysis of material structures using multivariate statistical analysis to identify and distinguish various phases, defects and symmetries.
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