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Butcher TA, Phillips NW, Chiu CC, Wei CC, Ho SZ, Chen YC, Fröjdh E, Baruffaldi F, Carulla M, Zhang J, Bergamaschi A, Vaz CAF, Kleibert A, Finizio S, Yang JC, Huang SW, Raabe J. Ptychographic Nanoscale Imaging of the Magnetoelectric Coupling in Freestanding BiFeO 3. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2024:e2311157. [PMID: 38402421 DOI: 10.1002/adma.202311157] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/24/2023] [Revised: 12/23/2023] [Indexed: 02/26/2024]
Abstract
Understanding the magnetic and ferroelectric ordering of magnetoelectric multiferroic materials at the nanoscale necessitates a versatile imaging method with high spatial resolution. Here, soft X-ray ptychography is employed to simultaneously image the ferroelectric and antiferromagnetic domains in an 80 nm thin freestanding film of the room-temperature multiferroic BiFeO3 (BFO). The antiferromagnetic spin cycloid of period 64 nm is resolved by reconstructing the corresponding resonant elastic X-ray scattering in real space and visualized together with mosaic-like ferroelectric domains in a linear dichroic contrast image at the Fe L3 edge. The measurements reveal a near perfect coupling between the antiferromagnetic and ferroelectric ordering by which the propagation direction of the spin cycloid is locked orthogonally to the ferroelectric polarization. In addition, the study evinces both a preference for in-plane propagation of the spin cycloid and changes of the ferroelectric polarization by 71° between multiferroic domains in the epitaxial strain-free, freestanding BFO film. The results provide a direct visualization of the strong magnetoelectric coupling in BFO and of its fine multiferroic domain structure, emphasizing the potential of ptychographic imaging for the study of multiferroics and non-collinear magnetic materials with soft X-rays.
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Affiliation(s)
- Tim A Butcher
- Paul Scherrer Institut, Villigen PSI, 5232, Switzerland
| | | | - Chun-Chien Chiu
- Department of Physics, National Cheng Kung University, Tainan, 70101, Taiwan
| | - Chia-Chun Wei
- Department of Physics, National Cheng Kung University, Tainan, 70101, Taiwan
| | - Sheng-Zhu Ho
- Department of Physics, National Cheng Kung University, Tainan, 70101, Taiwan
| | - Yi-Chun Chen
- Department of Physics, National Cheng Kung University, Tainan, 70101, Taiwan
| | - Erik Fröjdh
- Paul Scherrer Institut, Villigen PSI, 5232, Switzerland
| | | | - Maria Carulla
- Paul Scherrer Institut, Villigen PSI, 5232, Switzerland
| | - Jiaguo Zhang
- Paul Scherrer Institut, Villigen PSI, 5232, Switzerland
| | | | | | | | | | - Jan-Chi Yang
- Department of Physics, National Cheng Kung University, Tainan, 70101, Taiwan
- Center for Quantum Frontiers of Research & Technology (QFort), National Cheng Kung University, Tainan, 70101, Taiwan
| | | | - Jörg Raabe
- Paul Scherrer Institut, Villigen PSI, 5232, Switzerland
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Xu S, Wang J, Chen P, Jin K, Ma C, Wu S, Guo E, Ge C, Wang C, Xu X, Yao H, Wang J, Xie D, Wang X, Chang K, Bai X, Yang G. Magnetoelectric coupling in multiferroics probed by optical second harmonic generation. Nat Commun 2023; 14:2274. [PMID: 37080982 PMCID: PMC10119081 DOI: 10.1038/s41467-023-38055-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2023] [Accepted: 04/13/2023] [Indexed: 04/22/2023] Open
Abstract
Magnetoelectric coupling, as a fundamental physical nature and with the potential to add functionality to devices while also reducing energy consumption, has been challenging to be probed in freestanding membranes or two-dimensional materials due to their instability and fragility. In this paper, we report a magnetoelectric coupling probed by optical second harmonic generation with external magnetic field, and show the manipulation of the ferroelectric and antiferromagnetic orders by the magnetic and thermal fields in BiFeO3 films epitaxially grown on the substrates and in the freestanding ones. Here we define an optical magnetoelectric-coupling constant, denoting the ability of controlling light-induced nonlinear polarization by the magnetic field, and found the magnetoelectric-coupling was suppressed by strain releasing but remain robust against thermal fluctuation for freestanding BiFeO3.
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Affiliation(s)
- Shuai Xu
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, 100190, Beijing, China
- University of Chinese Academy of Sciences, 100049, Beijing, China
| | - Jiesu Wang
- Beijing Academy of Quantum Information Sciences, 100193, Beijing, China
| | - Pan Chen
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, 100190, Beijing, China
| | - Kuijuan Jin
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, 100190, Beijing, China.
- University of Chinese Academy of Sciences, 100049, Beijing, China.
- Songshan Lake Materials Laboratory, 523808, Dongguan, Guangdong, China.
| | - Cheng Ma
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, 100190, Beijing, China
- University of Chinese Academy of Sciences, 100049, Beijing, China
| | - Shiyao Wu
- Beijing Academy of Quantum Information Sciences, 100193, Beijing, China
| | - Erjia Guo
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, 100190, Beijing, China
- University of Chinese Academy of Sciences, 100049, Beijing, China
| | - Chen Ge
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, 100190, Beijing, China
- University of Chinese Academy of Sciences, 100049, Beijing, China
| | - Can Wang
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, 100190, Beijing, China
- University of Chinese Academy of Sciences, 100049, Beijing, China
- Songshan Lake Materials Laboratory, 523808, Dongguan, Guangdong, China
| | - Xiulai Xu
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, 100190, Beijing, China
- State Key Laboratory for Mesoscopic Physics and Frontiers Science Center for Nano-optoelectronics, School of Physics, Peking University, 100871, Beijing, China
| | - Hongbao Yao
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, 100190, Beijing, China
- University of Chinese Academy of Sciences, 100049, Beijing, China
| | - Jingyi Wang
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, 100190, Beijing, China
| | - Donggang Xie
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, 100190, Beijing, China
| | - Xinyan Wang
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, 100190, Beijing, China
- University of Chinese Academy of Sciences, 100049, Beijing, China
| | - Kai Chang
- Beijing Academy of Quantum Information Sciences, 100193, Beijing, China
| | - Xuedong Bai
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, 100190, Beijing, China
- University of Chinese Academy of Sciences, 100049, Beijing, China
- Songshan Lake Materials Laboratory, 523808, Dongguan, Guangdong, China
| | - Guozhen Yang
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, 100190, Beijing, China
- University of Chinese Academy of Sciences, 100049, Beijing, China
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Zhang JJ, Altalhi T, Yakobson BI. Flexo-Ferroelectricity and a Work Cycle of a Two-Dimensional-Monolayer Actuator. ACS NANO 2023; 17:5121-5128. [PMID: 36853621 DOI: 10.1021/acsnano.3c00492] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
Well recognized mechanical flexibility of two-dimensional (2D) materials is shown to bring about unexpected behaviors to the recently discovered monolayer ferroelectrics, especially those displaying normal, off-plane polarization. A "ferro-flexo" coupling term is introduced into the energy expression, to account for the connection of ferroelectricity and bending (strain gradient) of the layer, to predict and quantify its spontaneous curvature and how it affects the phase transitions. With InP as a chemically specific representative example, the first-principles calculations indeed reveal strong coupling ∼P·ϰ between the ferroelectric polarization (P) and the curvature of the layer (ϰ ≡ 1/r), having profound consequences for both mechanics and ferroelectricity of the material. Due to flexural relaxation, the spontaneous polarization and the transition barrier rise significantly, leading to large changes in the Curie temperature, coercive field, and domain wall width and energy, based on Monte Carlo simulations. On the other hand, the polarization switching, characteristic to ferroelectrics, does induce an overall layer bending, enabling a conversion of electrical signal to movement as an actuator; its possible work-cycles and maximum work-efficiency are briefly discussed.
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Affiliation(s)
- Jun-Jie Zhang
- Department of Materials Science and NanoEngineering, Rice University, Houston, Texas 77005, United States
| | - Tariq Altalhi
- Chemistry Department, Taif University, Taif 21974, Saudi Arabia
| | - Boris I Yakobson
- Chemistry Department, Taif University, Taif 21974, Saudi Arabia
- Department of Chemistry, Rice University, Houston, Texas 77005, United States
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Pesquera D, Fernández A, Khestanova E, Martin LW. Freestanding complex-oxide membranes. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2022; 34:383001. [PMID: 35779514 DOI: 10.1088/1361-648x/ac7dd5] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/22/2022] [Accepted: 07/01/2022] [Indexed: 06/15/2023]
Abstract
Complex oxides show a vast range of functional responses, unparalleled within the inorganic solids realm, making them promising materials for applications as varied as next-generation field-effect transistors, spintronic devices, electro-optic modulators, pyroelectric detectors, or oxygen reduction catalysts. Their stability in ambient conditions, chemical versatility, and large susceptibility to minute structural and electronic modifications make them ideal subjects of study to discover emergent phenomena and to generate novel functionalities for next-generation devices. Recent advances in the synthesis of single-crystal, freestanding complex oxide membranes provide an unprecedented opportunity to study these materials in a nearly-ideal system (e.g. free of mechanical/thermal interaction with substrates) as well as expanding the range of tools for tweaking their order parameters (i.e. (anti-)ferromagnetic, (anti-)ferroelectric, ferroelastic), and increasing the possibility of achieving novel heterointegration approaches (including interfacing dissimilar materials) by avoiding the chemical, structural, or thermal constraints in synthesis processes. Here, we review the recent developments in the fabrication and characterization of complex-oxide membranes and discuss their potential for unraveling novel physicochemical phenomena at the nanoscale and for further exploiting their functionalities in technologically relevant devices.
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Affiliation(s)
- David Pesquera
- Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and BIST Campus UAB, Bellaterra, Barcelona 08193, Spain
| | - Abel Fernández
- Department of Materials Science and Engineering, University of California, Berkeley, CA 94720, United States of America
| | | | - Lane W Martin
- Department of Materials Science and Engineering, University of California, Berkeley, CA 94720, United States of America
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, United States of America
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Fernandez A, Acharya M, Lee HG, Schimpf J, Jiang Y, Lou D, Tian Z, Martin LW. Thin-Film Ferroelectrics. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2022; 34:e2108841. [PMID: 35353395 DOI: 10.1002/adma.202108841] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Revised: 03/03/2022] [Indexed: 06/14/2023]
Abstract
Over the last 30 years, the study of ferroelectric oxides has been revolutionized by the implementation of epitaxial-thin-film-based studies, which have driven many advances in the understanding of ferroelectric physics and the realization of novel polar structures and functionalities. New questions have motivated the development of advanced synthesis, characterization, and simulations of epitaxial thin films and, in turn, have provided new insights and applications across the micro-, meso-, and macroscopic length scales. This review traces the evolution of ferroelectric thin-film research through the early days developing understanding of the roles of size and strain on ferroelectrics to the present day, where such understanding is used to create complex hierarchical domain structures, novel polar topologies, and controlled chemical and defect profiles. The extension of epitaxial techniques, coupled with advances in high-throughput simulations, now stands to accelerate the discovery and study of new ferroelectric materials. Coming hand-in-hand with these new materials is new understanding and control of ferroelectric functionalities. Today, researchers are actively working to apply these lessons in a number of applications, including novel memory and logic architectures, as well as a host of energy conversion devices.
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Affiliation(s)
- Abel Fernandez
- Department of Materials Science and Engineering, University of California, Berkeley, Berkeley, CA, 94720, USA
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Megha Acharya
- Department of Materials Science and Engineering, University of California, Berkeley, Berkeley, CA, 94720, USA
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Han-Gyeol Lee
- Department of Materials Science and Engineering, University of California, Berkeley, Berkeley, CA, 94720, USA
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Jesse Schimpf
- Department of Materials Science and Engineering, University of California, Berkeley, Berkeley, CA, 94720, USA
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Yizhe Jiang
- Department of Materials Science and Engineering, University of California, Berkeley, Berkeley, CA, 94720, USA
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Djamila Lou
- Department of Materials Science and Engineering, University of California, Berkeley, Berkeley, CA, 94720, USA
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Zishen Tian
- Department of Materials Science and Engineering, University of California, Berkeley, Berkeley, CA, 94720, USA
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Lane W Martin
- Department of Materials Science and Engineering, University of California, Berkeley, Berkeley, CA, 94720, USA
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
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Yi J, Liu L, Shu L, Huang Y, Li JF. Outstanding Ferroelectricity in Sol-Gel-Derived Polycrystalline BiFeO 3 Films within a Wide Thickness Range. ACS APPLIED MATERIALS & INTERFACES 2022; 14:21696-21704. [PMID: 35482048 DOI: 10.1021/acsami.2c03137] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
As a promising lead-free ferroelectric, BiFeO3 has a very large intrinsic polarization of ∼100 μC/cm2, enabling its great potential in electronic applications especially in a film format. In this sense, reliable ferroelectric properties are desired; however, pure-phase BiFeO3 films are notorious for their large leakage current, especially of those processed by using the sol-gel method─a facile and industrially scalable method for film preparation. In this study, a protection layer, which can be easily integrated in the sol-gel process, is used to ensure the acquirement of remnant polarization of ∼65 μC/cm2 in ∼200 nm BiFeO3 thin films, whereas O2 annealing can enhance that to ∼120 μC/cm2 in ∼400-700 nm films. Reliable ferroelectricity of BiFeO3 films on Si wafers within a wide thickness range was thus achieved. The obtained ferroelectricity is among the best-achieved properties to date of BiFeO3 films for both thin and intermediate thicknesses, including both chemically and physically derived. These results are helpful to advance potential use of sol-gel-processed BiFeO3 films in electromechanical devices with different desired thicknesses.
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Affiliation(s)
- Jiaojiao Yi
- Laboratory of Advanced Multicomponent Materials, School of Mechanical Engineering, Jiangsu University of Technology, Changzhou 213001, P. R. China
| | - Lisha Liu
- State Key Laboratory of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, 100084 Beijing, P. R. China
| | - Liang Shu
- State Key Laboratory of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, 100084 Beijing, P. R. China
| | - Yu Huang
- State Key Laboratory of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, 100084 Beijing, P. R. China
| | - Jing-Feng Li
- State Key Laboratory of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, 100084 Beijing, P. R. China
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