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Sánchez-Santolino G, Rouco V, Puebla S, Aramberri H, Zamora V, Cabero M, Cuellar FA, Munuera C, Mompean F, Garcia-Hernandez M, Castellanos-Gomez A, Íñiguez J, Leon C, Santamaria J. A 2D ferroelectric vortex pattern in twisted BaTiO 3 freestanding layers. Nature 2024; 626:529-534. [PMID: 38356067 PMCID: PMC10866709 DOI: 10.1038/s41586-023-06978-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Accepted: 12/14/2023] [Indexed: 02/16/2024]
Abstract
The wealth of complex polar topologies1-10 recently found in nanoscale ferroelectrics results from a delicate balance between the intrinsic tendency of the materials to develop a homogeneous polarization and the electric and mechanical boundary conditions imposed on them. Ferroelectric-dielectric interfaces are model systems in which polarization curling originates from open circuit-like electric boundary conditions, to avoid the build-up of polarization charges through the formation of flux-closure11-14 domains that evolve into vortex-like structures at the nanoscale15-17 level. Although ferroelectricity is known to couple strongly with strain (both homogeneous18 and inhomogeneous19,20), the effect of mechanical constraints21 on thin-film nanoscale ferroelectrics has been comparatively less explored because of the relative paucity of strain patterns that can be implemented experimentally. Here we show that the stacking of freestanding ferroelectric perovskite layers with controlled twist angles provides an opportunity to tailor these topological nanostructures in a way determined by the lateral strain modulation associated with the twisting. Furthermore, we find that a peculiar pattern of polarization vortices and antivortices emerges from the flexoelectric coupling of polarization to strain gradients. This finding provides opportunities to create two-dimensional high-density vortex crystals that would enable us to explore previously unknown physical effects and functionalities.
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Affiliation(s)
- G Sánchez-Santolino
- GFMC, Departamento Fisica de Materiales, Facultad de Fisica, Universidad Complutense, Madrid, Spain.
- Laboratorio de Heteroestructuras con aplicación en spintrónica, Unidad Asociada UCM/CSIC, Madrid, Spain.
| | - V Rouco
- GFMC, Departamento Fisica de Materiales, Facultad de Fisica, Universidad Complutense, Madrid, Spain.
| | - S Puebla
- Instituto de Ciencia de Materiales de Madrid ICMM-CSIC, Madrid, Spain
| | - H Aramberri
- Materials Research and Technology Department, Luxembourg Institute of Science and Technology (LIST), Esch-sur-Alzette, Luxembourg
| | - V Zamora
- GFMC, Departamento Fisica de Materiales, Facultad de Fisica, Universidad Complutense, Madrid, Spain
| | - M Cabero
- ICTS Centro Nacional de Microscopia Electrónica 'Luis Brú', Universidad Complutense, Madrid, Spain
| | - F A Cuellar
- GFMC, Departamento Fisica de Materiales, Facultad de Fisica, Universidad Complutense, Madrid, Spain
| | - C Munuera
- Laboratorio de Heteroestructuras con aplicación en spintrónica, Unidad Asociada UCM/CSIC, Madrid, Spain
- Instituto de Ciencia de Materiales de Madrid ICMM-CSIC, Madrid, Spain
| | - F Mompean
- Laboratorio de Heteroestructuras con aplicación en spintrónica, Unidad Asociada UCM/CSIC, Madrid, Spain
- Instituto de Ciencia de Materiales de Madrid ICMM-CSIC, Madrid, Spain
| | - M Garcia-Hernandez
- Laboratorio de Heteroestructuras con aplicación en spintrónica, Unidad Asociada UCM/CSIC, Madrid, Spain
- Instituto de Ciencia de Materiales de Madrid ICMM-CSIC, Madrid, Spain
| | - A Castellanos-Gomez
- Laboratorio de Heteroestructuras con aplicación en spintrónica, Unidad Asociada UCM/CSIC, Madrid, Spain
- Instituto de Ciencia de Materiales de Madrid ICMM-CSIC, Madrid, Spain
| | - J Íñiguez
- Materials Research and Technology Department, Luxembourg Institute of Science and Technology (LIST), Esch-sur-Alzette, Luxembourg
- Department of Physics and Materials Science, University of Luxembourg, Belvaux, Luxembourg
| | - C Leon
- GFMC, Departamento Fisica de Materiales, Facultad de Fisica, Universidad Complutense, Madrid, Spain
- Laboratorio de Heteroestructuras con aplicación en spintrónica, Unidad Asociada UCM/CSIC, Madrid, Spain
| | - J Santamaria
- GFMC, Departamento Fisica de Materiales, Facultad de Fisica, Universidad Complutense, Madrid, Spain.
- Laboratorio de Heteroestructuras con aplicación en spintrónica, Unidad Asociada UCM/CSIC, Madrid, Spain.
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2
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Jiang W, Wang S, Yang X, Yang J. Effect of Aspect Ratio of Ferroelectric Nanofilms on Polarization Vortex Stability under Uniaxial Tension or Compression. MATERIALS (BASEL, SWITZERLAND) 2023; 16:7699. [PMID: 38138840 PMCID: PMC10744852 DOI: 10.3390/ma16247699] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2023] [Revised: 11/30/2023] [Accepted: 12/12/2023] [Indexed: 12/24/2023]
Abstract
Mastering the variations in the stability of a polarization vortex is fundamental for the development of ferroelectric devices based on polarization vortex domain structures. Some phase field simulations were conducted on PbTiO3 nanofilms with an initial polarization vortex under uniaxial tension or compression to investigate the conditions of vortex instability and the effects of aspect ratio of nanofilms and temperature on them. The instability of a polarization vortex is strongly dependent on aspect ratio and temperature. The critical compressive stress increases with decreasing aspect ratio under the action of compressive stress. However, the critical tensile stress first decreases and then increases with decreasing aspect ratio, then continues to decrease. There are two inflection points in the curve. In addition, an elevated temperature makes both the critical tensile and compressive stresses decline, and will also cause the aspect ratio corresponding to the inflection point to decrease. These are very important for the design of promising nano-ferroelectric devices based on polarization vortices to improve their performance while maintaining storage density.
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Affiliation(s)
- Wenkai Jiang
- School of Mechanical Engineering, Wuhan Polytechnic University, Wuhan 430048, China; (W.J.)
| | - Sen Wang
- School of Mechanical Engineering, Wuhan Polytechnic University, Wuhan 430048, China; (W.J.)
| | - Xinhua Yang
- School of Transportation, Civil Engineering and Architecture, Foshan University, Foshan 528200, China;
| | - Junsheng Yang
- School of Mechanical Engineering, Wuhan Polytechnic University, Wuhan 430048, China; (W.J.)
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3
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McCarter MR, Kim KT, Stoica VA, Das S, Klewe C, Donoway EP, Burn DM, Shafer P, Rodolakis F, Gonçalves MAP, Gómez-Ortiz F, Íñiguez J, García-Fernández P, Junquera J, Lovesey SW, van der Laan G, Park SY, Freeland JW, Martin LW, Lee DR, Ramesh R. Structural Chirality of Polar Skyrmions Probed by Resonant Elastic X-Ray Scattering. PHYSICAL REVIEW LETTERS 2022; 129:247601. [PMID: 36563236 DOI: 10.1103/physrevlett.129.247601] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/12/2021] [Revised: 03/08/2022] [Accepted: 10/23/2022] [Indexed: 06/17/2023]
Abstract
An escalating challenge in condensed-matter research is the characterization of emergent order-parameter nanostructures such as ferroelectric and ferromagnetic skyrmions. Their small length scales coupled with complex, three-dimensional polarization or spin structures makes them demanding to trace out fully. Resonant elastic x-ray scattering (REXS) has emerged as a technique to study chirality in spin textures such as skyrmions and domain walls. It has, however, been used to a considerably lesser extent to study analogous features in ferroelectrics. Here, we present a framework for modeling REXS from an arbitrary arrangement of charge quadrupole moments, which can be applied to nanostructures in materials such as ferroelectrics. With this, we demonstrate how extended reciprocal space scans using REXS with circularly polarized x rays can probe the three-dimensional structure and chirality of polar skyrmions. Measurements, bolstered by quantitative scattering calculations, show that polar skyrmions of mixed chirality coexist, and that REXS allows valuation of relative fractions of right- and left-handed skyrmions. Our quantitative analysis of the structure and chirality of polar skyrmions highlights the capability of REXS for establishing complex topological structures toward future application exploits.
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Affiliation(s)
- Margaret R McCarter
- Department of Physics, University of California, Berkeley, California 94720, USA
| | - Kook Tae Kim
- Department of Physics, Soongsil University, Seoul 06978, Korea
| | - Vladimir A Stoica
- Advanced Photon Source, Argonne National Laboratory, Lemont, Illinois 60439, USA
- Department of Materials Science and Engineering, Pennsylvania State University, Pennsylvania 16802, USA
| | - Sujit Das
- Materials Research Centre, Indian Institute of Science, Bangalore 560012, India
| | - Christoph Klewe
- Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - Elizabeth P Donoway
- Department of Physics, University of California, Berkeley, California 94720, USA
| | - David M Burn
- Diamond Light Source, Harwell Science and Innovation Campus, Didcot, Oxfordshire OX11 0DE, United Kingdom
| | - Padraic Shafer
- Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - Fanny Rodolakis
- Advanced Photon Source, Argonne National Laboratory, Lemont, Illinois 60439, USA
| | - Mauro A P Gonçalves
- Institute of Physics of the Czech Academy of Sciences, 18221 Prague 8, Czech Republic
| | - Fernando Gómez-Ortiz
- Departmento de Ciencias de la Tierra y Física de la Materia Condensada, Universidad de Cantabria, 39005 Santander, Spain
| | - Jorge Íñiguez
- Materials Research and Technology Department, Luxembourg Institute of Science and Technology (LIST), 5 avenue des Hauts-Fourneaux, L-4362 Esch/Alzette, Luxemburg
- Department of Physics and Materials Science, University of Luxembourg, Rue du Brill 41, L-4422 Belvaux, Luxembourg
| | - Pablo García-Fernández
- Departmento de Ciencias de la Tierra y Física de la Materia Condensada, Universidad de Cantabria, 39005 Santander, Spain
| | - Javier Junquera
- Departmento de Ciencias de la Tierra y Física de la Materia Condensada, Universidad de Cantabria, 39005 Santander, Spain
| | - Stephen W Lovesey
- Diamond Light Source, Harwell Science and Innovation Campus, Didcot, Oxfordshire OX11 0DE, United Kingdom
- Department of Physics, Oxford University, Oxford OX1 3PU, United Kingdom
| | - Gerrit van der Laan
- Diamond Light Source, Harwell Science and Innovation Campus, Didcot, Oxfordshire OX11 0DE, United Kingdom
| | - Se Young Park
- Department of Physics, Soongsil University, Seoul 06978, Korea
| | - John W Freeland
- Advanced Photon Source, Argonne National Laboratory, Lemont, Illinois 60439, USA
| | - Lane W Martin
- Department of Materials Science and Engineering, University of California, Berkeley, California 94720, USA
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - Dong Ryeol Lee
- Department of Physics, Soongsil University, Seoul 06978, Korea
| | - Ramamoorthy Ramesh
- Department of Physics, University of California, Berkeley, California 94720, USA
- Department of Materials Science and Engineering, University of California, Berkeley, California 94720, USA
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
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4
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Nonvolatile ferroelectric domain wall memory integrated on silicon. Nat Commun 2022; 13:4332. [PMID: 35882838 PMCID: PMC9325887 DOI: 10.1038/s41467-022-31763-w] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2021] [Accepted: 07/01/2022] [Indexed: 11/30/2022] Open
Abstract
Ferroelectric domain wall memories have been proposed as a promising candidate for nonvolatile memories, given their intriguing advantages including low energy consumption and high-density integration. Perovskite oxides possess superior ferroelectric prosperities but perovskite-based domain wall memory integrated on silicon has rarely been reported due to the technical challenges in the sample preparation. Here, we demonstrate a domain wall memory prototype utilizing freestanding BaTiO3 membranes transferred onto silicon. While as-grown BaTiO3 films on (001) SrTiO3 substrate are purely c-axis polarized, we find they exhibit distinct in-plane multidomain structures after released from the substrate and integrated onto silicon due to the collective effects from depolarizing field and strain relaxation. Based on the strong in-plane ferroelectricity, conductive domain walls with reading currents up to nanoampere are observed and can be both created and erased artificially, highlighting the great potential of the integration of perovskite oxides with silicon for ferroelectric domain wall memories. Integrating ferroelectric perovskite oxides on Si is highly desired for electronic applications but challenging. Here, the authors show emergent in-plane ferroelectricity and promising nonvolatile memories based on resistive domain wall in BaTiO3/Si.
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5
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Abstract
Ferroelectric materials manifest unique dielectric, ferroelastic, and piezoelectric properties. A targeted design of ferroelectrics at the nanoscale is not only of fundamental appeal but holds the highest potential for applications. Compared to two-dimensional nanostructures such as thin films and superlattices, one-dimensional ferroelectric nanowires are investigated to a much lesser extent. Here, we reveal a variety of the topological polarization states, particularly the vortex and helical chiral phases, in loaded ferroelectric nanowires, which enable us to complete the strain–temperature phase diagram of the one-dimensional ferroelectrics. These phases are of prime importance for optoelectronics and quantum communication technologies.
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6
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Improvements of Electrical Characteristics in Poly-Si Nanowires Thin-Film Transistors with External Connection of a BiFeO 3 Capacitor. MEMBRANES 2021; 11:membranes11100758. [PMID: 34677524 PMCID: PMC8538922 DOI: 10.3390/membranes11100758] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/06/2021] [Revised: 09/23/2021] [Accepted: 09/29/2021] [Indexed: 11/16/2022]
Abstract
By a sol–gel method, a BiFeO3 (BFO) capacitor is fabricated and connected with the control thin film transistor (TFT). Compared with a control thin-film transistor, the proposed BFO TFT achieves 56% drive current enhancement and 7–28% subthreshold swing (SS) reduction. Moreover, the effect of the proposed BiFeO3 capacitor on IDS-VGS hysteresis in the BFO TFT is 0.1–0.2 V. Because dVint/dVGS > 1 is obtained at a wide range of VGS, it reveals that the incomplete dipole flipping is a major mechanism to obtain improved SS and a small hysteresis effect in the BFO TFT. Experimental results indicate that sol-gel BFO TFT is a potential candidate for digital application.
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Chen S, Yuan S, Hou Z, Tang Y, Zhang J, Wang T, Li K, Zhao W, Liu X, Chen L, Martin LW, Chen Z. Recent Progress on Topological Structures in Ferroic Thin Films and Heterostructures. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2021; 33:e2000857. [PMID: 32815214 DOI: 10.1002/adma.202000857] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/06/2020] [Revised: 04/17/2020] [Indexed: 06/11/2023]
Abstract
Topological spin/polarization structures in ferroic materials continue to draw great attention as a result of their fascinating physical behaviors and promising applications in the field of high-density nonvolatile memories as well as future energy-efficient nanoelectronic and spintronic devices. Such developments have been made, in part, based on recent advances in theoretical calculations, the synthesis of high-quality thin films, and the characterization of their emergent phenomena and exotic phases. Herein, progress over the last decade in the study of topological structures in ferroic thin films and heterostructures is explored, including the observation of topological structures and control of their structures and emergent physical phenomena through epitaxial strain, layer thickness, electric, magnetic fields, etc. First, the evolution of topological spin structures (e.g., magnetic skyrmions) and associated functionalities (e.g., topological Hall effect) in magnetic thin films and heterostructures is discussed. Then, the exotic polar topologies (e.g., domain walls, closure domains, polar vortices, bubble domains, and polar skyrmions) and their emergent physical properties in ferroelectric oxide films and heterostructures are explored. Finally, a brief overview and prospectus of how the field may evolve in the coming years is provided.
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Affiliation(s)
- Shanquan Chen
- School of Materials Science and Engineering, Harbin Institute of Technology, Shenzhen, 518055, China
| | - Shuai Yuan
- School of Materials Science and Engineering, Harbin Institute of Technology, Shenzhen, 518055, China
| | - Zhipeng Hou
- Guangdong Provincial Key Laboratory of Optical Information Materials and Technology & Institute for Advanced Materials, South China Academy of Advanced Optoelectronics, South China Normal University, Guangzhou, 510006, P. R. China
- National Center for International Research on Green Optoelectronics, South China Normal University, Guangzhou, 510006, P. R. China
| | - Yunlong Tang
- Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Wenhua Road 72, Shenyang, 110016, China
| | - Jinping Zhang
- School of Materials Science and Engineering, Harbin Institute of Technology, Shenzhen, 518055, China
| | - Tao Wang
- School of Materials Science and Engineering, Harbin Institute of Technology, Shenzhen, 518055, China
| | - Kang Li
- Flexible Printed Electronics Technology Center, Harbin Institute of Technology, Shenzhen, 518055, China
| | - Weiwei Zhao
- School of Materials Science and Engineering, Harbin Institute of Technology, Shenzhen, 518055, China
- Flexible Printed Electronics Technology Center, Harbin Institute of Technology, Shenzhen, 518055, China
| | - Xingjun Liu
- School of Materials Science and Engineering, Harbin Institute of Technology, Shenzhen, 518055, China
| | - Lang Chen
- Department of Physics, Southern University of Science and Technology, Shenzhen, 518055, China
| | - Lane W Martin
- Department of Materials Science and Engineering, University of California, Berkeley, CA, 94720, USA
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Zuhuang Chen
- School of Materials Science and Engineering, Harbin Institute of Technology, Shenzhen, 518055, China
- Flexible Printed Electronics Technology Center, Harbin Institute of Technology, Shenzhen, 518055, China
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8
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Sun Y, Abid AY, Tan C, Ren C, Li M, Li N, Chen P, Li Y, Zhang J, Zhong X, Wang J, Liao M, Liu K, Bai X, Zhou Y, Yu D, Gao P. Subunit cell-level measurement of polarization in an individual polar vortex. SCIENCE ADVANCES 2019; 5:eaav4355. [PMID: 31700996 PMCID: PMC6824850 DOI: 10.1126/sciadv.aav4355] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2018] [Accepted: 09/14/2019] [Indexed: 05/18/2023]
Abstract
Recently, several captivating topological structures of electric dipole moments (e.g., vortex, flux closure) have been reported in ferroelectrics with reduced size/dimensions. However, accurate polarization distribution of these topological ferroelectric structures has never been experimentally obtained. We precisely measure the polarization distribution of an individual ferroelectric vortex in PbTiO3/SrTiO3 superlattices at the subunit cell level by using the atomically resolved integrated differential phase contrast imaging in an aberration-corrected scanning transmission electron microscope. We find, in vortices, that out-of-plane polarization is larger than in-plane polarization, and that downward polarization is larger than upward polarization. The polarization magnitude is closely related to tetragonality. Moreover, the contribution of the Pb─O bond to total polarization is highly inhomogeneous in vortices. Our precise measurement at the subunit cell scale provides a sound foundation for mechanistic understanding of the structure and properties of a ferroelectric vortex and lattice-charge coupling phenomena in these topological ferroelectric structures.
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Affiliation(s)
- Yuanwei Sun
- International Center for Quantum Materials, Peking University, Beijing 100871, China
- Electron Microscopy Laboratory, School of Physics, Peking University, Beijing 100871, China
| | - Adeel Y. Abid
- International Center for Quantum Materials, Peking University, Beijing 100871, China
- Electron Microscopy Laboratory, School of Physics, Peking University, Beijing 100871, China
| | - Congbing Tan
- School of Materials Science and Engineering, Xiangtan University, Hunan, Xiangtan 411105, China
| | - Chuanlai Ren
- School of Materials Science and Engineering, Xiangtan University, Hunan, Xiangtan 411105, China
| | - Mingqiang Li
- International Center for Quantum Materials, Peking University, Beijing 100871, China
- Electron Microscopy Laboratory, School of Physics, Peking University, Beijing 100871, China
| | - Ning Li
- International Center for Quantum Materials, Peking University, Beijing 100871, China
- Electron Microscopy Laboratory, School of Physics, Peking University, Beijing 100871, China
| | - Pan Chen
- State Key Laboratory for Surface Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Yuehui Li
- International Center for Quantum Materials, Peking University, Beijing 100871, China
- Electron Microscopy Laboratory, School of Physics, Peking University, Beijing 100871, China
| | - Jingmin Zhang
- Electron Microscopy Laboratory, School of Physics, Peking University, Beijing 100871, China
| | - Xiangli Zhong
- School of Materials Science and Engineering, Xiangtan University, Hunan, Xiangtan 411105, China
- Corresponding author. (X.Z.); (P.G.)
| | - Jinbin Wang
- School of Materials Science and Engineering, Xiangtan University, Hunan, Xiangtan 411105, China
| | - Min Liao
- School of Materials Science and Engineering, Xiangtan University, Hunan, Xiangtan 411105, China
| | - Kaihui Liu
- State Key Laboratory for Artificial Microstructure and Mesoscopic Physics, School of Physics, Peking University, Beijing 100871, China
- Collaborative Innovation Center of Quantum Matter, Beijing 100871, China
| | - Xuedong Bai
- State Key Laboratory for Surface Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- Collaborative Innovation Center of Quantum Matter, Beijing 100871, China
| | - Yichun Zhou
- School of Materials Science and Engineering, Xiangtan University, Hunan, Xiangtan 411105, China
| | - Dapeng Yu
- State Key Laboratory for Artificial Microstructure and Mesoscopic Physics, School of Physics, Peking University, Beijing 100871, China
- Collaborative Innovation Center of Quantum Matter, Beijing 100871, China
- Shenzhen Key Laboratory of Quantum Science and Engineering, Shenzhen 518055, China
| | - Peng Gao
- International Center for Quantum Materials, Peking University, Beijing 100871, China
- Electron Microscopy Laboratory, School of Physics, Peking University, Beijing 100871, China
- Collaborative Innovation Center of Quantum Matter, Beijing 100871, China
- Corresponding author. (X.Z.); (P.G.)
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9
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Huang W, Li S, Bouzidi S, Lei L, Zhang Z, Xu P, Cloutier SG, Rosei F, Nechache R. Epitaxial patterned Bi 2FeCrO 6 nanoisland arrays with room temperature multiferroic properties. NANOSCALE ADVANCES 2019; 1:2139-2145. [PMID: 36131975 PMCID: PMC9419458 DOI: 10.1039/c9na00111e] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/22/2019] [Accepted: 05/11/2019] [Indexed: 06/15/2023]
Abstract
Epitaxial multiferroic Bi2FeCrO6 nanoisland arrays with a lateral size of ∼100 nm have been successfully fabricated by patterned SiO2 template-assisted pulsed laser deposition. The as-grown island structure exhibits promising multiferroic properties (i.e. ferroelectric and magnetic) even at nanometer dimensions at room temperature. This work demonstrates an effective strategy to fabricate high-density nonvolatile ferroelectric/multiferroic memory devices.
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Affiliation(s)
- Wei Huang
- INRS-Centre Énergie, Matériaux et Télécommunications 1650, Boulevard Lionel-Boulet Varennes Québec J3X 1S2 Canada
| | - Shun Li
- SUSTech Academy for Advanced Interdisciplinary Studies, Southern University of Science and Technology Shenzhen 518055 The People's Republic of China
- School of Environmental Science and Engineering, Southern University of Science and Technology Shenzhen 518055 The People's Republic of China
| | - Soraya Bouzidi
- École de Technologie Supérieure 1100 Rue Notre-Dame Ouest Montréal Québec H3C 1K3 Canada
| | - Lei Lei
- College of Electronic Science and Technology, Shenzhen University Nanhai Ave 3688 Shenzhen 518060 The People's Republic of China
| | - Zuotai Zhang
- School of Environmental Science and Engineering, Southern University of Science and Technology Shenzhen 518055 The People's Republic of China
| | - Ping Xu
- College of Electronic Science and Technology, Shenzhen University Nanhai Ave 3688 Shenzhen 518060 The People's Republic of China
| | - Sylvain G Cloutier
- École de Technologie Supérieure 1100 Rue Notre-Dame Ouest Montréal Québec H3C 1K3 Canada
| | - Federico Rosei
- INRS-Centre Énergie, Matériaux et Télécommunications 1650, Boulevard Lionel-Boulet Varennes Québec J3X 1S2 Canada
| | - Riad Nechache
- École de Technologie Supérieure 1100 Rue Notre-Dame Ouest Montréal Québec H3C 1K3 Canada
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10
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Park J, Mangeri J, Zhang Q, Yusuf MH, Pateras A, Dawber M, Holt MV, Heinonen OG, Nakhmanson S, Evans PG. Domain alignment within ferroelectric/dielectric PbTiO 3/SrTiO 3 superlattice nanostructures. NANOSCALE 2018; 10:3262-3271. [PMID: 29384166 DOI: 10.1039/c7nr07203a] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The ferroelectric domain pattern within lithographically defined PbTiO3/SrTiO3 ferroelectric/dielectric heteroepitaxial superlattice nanostructures is strongly influenced by the edges of the structures. Synchrotron X-ray nanobeam diffraction reveals that the spontaneously formed 180° ferroelectric stripe domains exhibited by such superlattices adopt a configuration in rectangular nanostructures in which domain walls are aligned with long patterned edges. The angular distribution of X-ray diffuse scattering intensity from nanodomains indicates that domains are aligned within an angular range of approximately 20° with respect to the edges. Computational studies based on a time-dependent Landau-Ginzburg-Devonshire model show that the preferred direction of the alignment results from lowering of the bulk and electrostrictive contributions to the free energy of the system due to the release of the lateral mechanical constraint. This unexpected alignment appears to be intrinsic and not a result of distortions or defects caused by the patterning process. Our work demonstrates how nanostructuring and patterning of heteroepitaxial superlattices allow for pathways to create and control ferroelectric structures that may appear counterintuitive.
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Affiliation(s)
- Joonkyu Park
- Department of Materials Science and Engineering, University of Wisconsin-Madison, Madison, WI 53706, USA.
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11
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Damodaran AR, Clarkson JD, Hong Z, Liu H, Yadav AK, Nelson CT, Hsu SL, McCarter MR, Park KD, Kravtsov V, Farhan A, Dong Y, Cai Z, Zhou H, Aguado-Puente P, García-Fernández P, Íñiguez J, Junquera J, Scholl A, Raschke MB, Chen LQ, Fong DD, Ramesh R, Martin LW. Phase coexistence and electric-field control of toroidal order in oxide superlattices. NATURE MATERIALS 2017; 16:1003-1009. [PMID: 28783161 DOI: 10.1038/nmat4951] [Citation(s) in RCA: 71] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/17/2016] [Accepted: 06/28/2017] [Indexed: 06/07/2023]
Abstract
Systems that exhibit phase competition, order parameter coexistence, and emergent order parameter topologies constitute a major part of modern condensed-matter physics. Here, by applying a range of characterization techniques, and simulations, we observe that in PbTiO3/SrTiO3 superlattices all of these effects can be found. By exploring superlattice period-, temperature- and field-dependent evolution of these structures, we observe several new features. First, it is possible to engineer phase coexistence mediated by a first-order phase transition between an emergent, low-temperature vortex phase with electric toroidal order and a high-temperature ferroelectric a1/a2 phase. At room temperature, the coexisting vortex and ferroelectric phases form a mesoscale, fibre-textured hierarchical superstructure. The vortex phase possesses an axial polarization, set by the net polarization of the surrounding ferroelectric domains, such that it possesses a multi-order-parameter state and belongs to a class of gyrotropic electrotoroidal compounds. Finally, application of electric fields to this mixed-phase system permits interconversion between the vortex and the ferroelectric phases concomitant with order-of-magnitude changes in piezoelectric and nonlinear optical responses. Our findings suggest new cross-coupled functionalities.
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Affiliation(s)
- A R Damodaran
- Department of Materials Science and Engineering, University of California, Berkeley, California 94720, USA
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - J D Clarkson
- Department of Materials Science and Engineering, University of California, Berkeley, California 94720, USA
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - Z Hong
- Department of Materials Science and Engineering, Pennsylvania State University, State College, Pennsylvania 16802, USA
| | - H Liu
- Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - A K Yadav
- Department of Materials Science and Engineering, University of California, Berkeley, California 94720, USA
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
- School of Electrical Engineering and Computer Science, UC Berkeley, Berkeley, California 94720, USA
| | - C T Nelson
- Department of Materials Science and Engineering, University of California, Berkeley, California 94720, USA
- National Center for Electron Microscopy, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - S-L Hsu
- Department of Materials Science and Engineering, University of California, Berkeley, California 94720, USA
- National Center for Electron Microscopy, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - M R McCarter
- Department of Physics, University of California, Berkeley, Berkeley, California 94720, USA
| | - K-D Park
- Department of Physics, Department of Chemistry, and JILA, University of Colorado, Boulder, Boulder, Colorado 80309, USA
| | - V Kravtsov
- Department of Physics, Department of Chemistry, and JILA, University of Colorado, Boulder, Boulder, Colorado 80309, USA
| | - A Farhan
- Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - Y Dong
- Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - Z Cai
- X-ray Science Division, Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - H Zhou
- X-ray Science Division, Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - P Aguado-Puente
- Centro de Física de Materiales, Universidad del País Vasco, 20018 San Sebastián, Spain
- Donostia International Physics Center, 20018 San Sebastián, Spain
| | - P García-Fernández
- Departmento de Ciencias de la Tierra y Física de la Materia Condensada, Universidad de Cantabria, Cantabria Campus Internacional, avenida de los Castros s/n, 39005 Santander, Spain
| | - J Íñiguez
- Materials Research and Technology Department, Luxembourg Institute of Science and Technology (LIST), 5 avenue des Hauts-Fourneaux, L-4362 Esch/Alzette, Luxembourg
| | - J Junquera
- Departmento de Ciencias de la Tierra y Física de la Materia Condensada, Universidad de Cantabria, Cantabria Campus Internacional, avenida de los Castros s/n, 39005 Santander, Spain
| | - A Scholl
- Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - M B Raschke
- Department of Physics, Department of Chemistry, and JILA, University of Colorado, Boulder, Boulder, Colorado 80309, USA
| | - L-Q Chen
- Department of Materials Science and Engineering, Pennsylvania State University, State College, Pennsylvania 16802, USA
| | - D D Fong
- Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - R Ramesh
- Department of Materials Science and Engineering, University of California, Berkeley, California 94720, USA
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
- Department of Physics, University of California, Berkeley, Berkeley, California 94720, USA
| | - L W Martin
- Department of Materials Science and Engineering, University of California, Berkeley, California 94720, USA
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
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12
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Zheng Y, Chen WJ. Characteristics and controllability of vortices in ferromagnetics, ferroelectrics, and multiferroics. REPORTS ON PROGRESS IN PHYSICS. PHYSICAL SOCIETY (GREAT BRITAIN) 2017; 80:086501. [PMID: 28155849 DOI: 10.1088/1361-6633/aa5e03] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Topological defects in condensed matter are attracting e significant attention due to their important role in phase transition and their fascinating characteristics. Among the various types of matter, ferroics which possess a switchable physical characteristic and form domain structure are ideal systems to form topological defects. In particular, a special class of topological defects-vortices-have been found to commonly exist in ferroics. They often manifest themselves as singular regions where domains merge in large systems, or stabilize as novel order states instead of forming domain structures in small enough systems. Understanding the characteristics and controllability of vortices in ferroics can provide us with deeper insight into the phase transition of condensed matter and also exciting opportunities in designing novel functional devices such as nano-memories, sensors, and transducers based on topological defects. In this review, we summarize the recent experimental and theoretical progress in ferroic vortices, with emphasis on those spin/dipole vortices formed in nanoscale ferromagnetics and ferroelectrics, and those structural domain vortices formed in multiferroic hexagonal manganites. We begin with an overview of this field. The fundamental concepts of ferroic vortices, followed by the theoretical simulation and experimental methods to explore ferroic vortices, are then introduced. The various characteristics of vortices (e.g. formation mechanisms, static/dynamic features, and electronic properties) and their controllability (e.g. by size, geometry, external thermal, electrical, magnetic, or mechanical fields) in ferromagnetics, ferroelectrics, and multiferroics are discussed in detail in individual sections. Finally, we conclude this review with an outlook on this rapidly developing field.
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Affiliation(s)
- Yue Zheng
- State Key Laboratory of Optoelectronic Materials and Technologies, School of Physics, Sun Yat-sen University, Guangzhou 510275, Guangdong, People's Republic of China. Micro&Nano Physics and Mechanics Research Laboratory, School of Physics, Sun Yat-sen University, Guangzhou 510275, Guangdong, People's Republic of China
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13
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Li Z, Wang Y, Tian G, Li P, Zhao L, Zhang F, Yao J, Fan H, Song X, Chen D, Fan Z, Qin M, Zeng M, Zhang Z, Lu X, Hu S, Lei C, Zhu Q, Li J, Gao X, Liu JM. High-density array of ferroelectric nanodots with robust and reversibly switchable topological domain states. SCIENCE ADVANCES 2017; 3:e1700919. [PMID: 28835925 PMCID: PMC5562417 DOI: 10.1126/sciadv.1700919] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/24/2017] [Accepted: 07/16/2017] [Indexed: 05/04/2023]
Abstract
The exotic topological domains in ferroelectrics and multiferroics have attracted extensive interest in recent years due to their novel functionalities and potential applications in nanoelectronic devices. One of the key challenges for these applications is a realization of robust yet reversibly switchable nanoscale topological domain states with high density, wherein spontaneous topological structures can be individually addressed and controlled. This has been accomplished in our work using high-density arrays of epitaxial BiFeO3 (BFO) ferroelectric nanodots with a lateral size as small as ~60 nm. We demonstrate various types of spontaneous topological domain structures, including center-convergent domains, center-divergent domains, and double-center domains, which are stable over sufficiently long time but can be manipulated and reversibly switched by electric field. The formation mechanisms of these topological domain states, assisted by the accumulation of compensating charges on the surface, have also been revealed. These results demonstrated that these reversibly switchable topological domain arrays are promising for applications in high-density nanoferroelectric devices such as nonvolatile memories.
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Affiliation(s)
- Zhongwen Li
- Institute for Advanced Materials and Guangdong Provincial Key Laboratory of Quantum Engineering and Quantum Materials, South China Normal University, Guangzhou 510006, China
| | - Yujia Wang
- Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, 72 Wenhua Road, Shenyang 110016, China
| | - Guo Tian
- Institute for Advanced Materials and Guangdong Provincial Key Laboratory of Quantum Engineering and Quantum Materials, South China Normal University, Guangzhou 510006, China
| | - Peilian Li
- Institute for Advanced Materials and Guangdong Provincial Key Laboratory of Quantum Engineering and Quantum Materials, South China Normal University, Guangzhou 510006, China
| | - Lina Zhao
- Institute for Advanced Materials and Guangdong Provincial Key Laboratory of Quantum Engineering and Quantum Materials, South China Normal University, Guangzhou 510006, China
| | - Fengyuan Zhang
- Institute for Advanced Materials and Guangdong Provincial Key Laboratory of Quantum Engineering and Quantum Materials, South China Normal University, Guangzhou 510006, China
| | - Junxiang Yao
- Institute for Advanced Materials and Guangdong Provincial Key Laboratory of Quantum Engineering and Quantum Materials, South China Normal University, Guangzhou 510006, China
| | - Hua Fan
- Institute for Advanced Materials and Guangdong Provincial Key Laboratory of Quantum Engineering and Quantum Materials, South China Normal University, Guangzhou 510006, China
| | - Xiao Song
- Institute for Advanced Materials and Guangdong Provincial Key Laboratory of Quantum Engineering and Quantum Materials, South China Normal University, Guangzhou 510006, China
| | - Deyang Chen
- Institute for Advanced Materials and Guangdong Provincial Key Laboratory of Quantum Engineering and Quantum Materials, South China Normal University, Guangzhou 510006, China
| | - Zhen Fan
- Institute for Advanced Materials and Guangdong Provincial Key Laboratory of Quantum Engineering and Quantum Materials, South China Normal University, Guangzhou 510006, China
| | - Minghui Qin
- Institute for Advanced Materials and Guangdong Provincial Key Laboratory of Quantum Engineering and Quantum Materials, South China Normal University, Guangzhou 510006, China
| | - Min Zeng
- Institute for Advanced Materials and Guangdong Provincial Key Laboratory of Quantum Engineering and Quantum Materials, South China Normal University, Guangzhou 510006, China
| | - Zhang Zhang
- Institute for Advanced Materials and Guangdong Provincial Key Laboratory of Quantum Engineering and Quantum Materials, South China Normal University, Guangzhou 510006, China
| | - Xubing Lu
- Institute for Advanced Materials and Guangdong Provincial Key Laboratory of Quantum Engineering and Quantum Materials, South China Normal University, Guangzhou 510006, China
| | - Shejun Hu
- Institute for Advanced Materials and Guangdong Provincial Key Laboratory of Quantum Engineering and Quantum Materials, South China Normal University, Guangzhou 510006, China
| | - Chihou Lei
- Department of Aerospace and Mechanical Engineering, Saint Louis University, St. Louis, MO 63103–1110, USA
| | - Qingfeng Zhu
- Shenzhen Key Laboratory of Nanobiomechanics, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, Guangdong 518055, China
| | - Jiangyu Li
- Shenzhen Key Laboratory of Nanobiomechanics, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, Guangdong 518055, China
- Department of Mechanical Engineering, University of Washington, Seattle, WA 98195–2600, USA
| | - Xingsen Gao
- Institute for Advanced Materials and Guangdong Provincial Key Laboratory of Quantum Engineering and Quantum Materials, South China Normal University, Guangzhou 510006, China
- Corresponding author. (X.G.); (J.-M.L.)
| | - Jun-Ming Liu
- Institute for Advanced Materials and Guangdong Provincial Key Laboratory of Quantum Engineering and Quantum Materials, South China Normal University, Guangzhou 510006, China
- National Laboratory of Solid State Microstructures and Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 21009, China
- Corresponding author. (X.G.); (J.-M.L.)
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Bin-Omran S. Influence of strain on an epitaxial ferroelectric (Ba 0.50 Sr 0.50 )TiO 3 nanodot under different electrical boundary conditions. PHYSICA E: LOW-DIMENSIONAL SYSTEMS AND NANOSTRUCTURES 2017; 86:58-63. [DOI: 10.1016/j.physe.2016.10.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/01/2023]
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15
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Mangeri J, Espinal Y, Jokisaari A, Pamir Alpay S, Nakhmanson S, Heinonen O. Topological phase transformations and intrinsic size effects in ferroelectric nanoparticles. NANOSCALE 2017; 9:1616-1624. [PMID: 28074199 DOI: 10.1039/c6nr09111c] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Composite materials comprised of ferroelectric nanoparticles in a dielectric matrix are being actively investigated for a variety of functional properties attractive for a wide range of novel electronic and energy harvesting devices. However, the dependence of these functionalities on shapes, sizes, orientation and mutual arrangement of ferroelectric particles is currently not fully understood. In this study, we utilize a time-dependent Ginzburg-Landau approach combined with coupled-physics finite-element-method based simulations to elucidate the behavior of polarization in isolated spherical PbTiO3 or BaTiO3 nanoparticles embedded in a dielectric medium, including air. The equilibrium polarization topology is strongly affected by particle diameter, as well as the choice of inclusion and matrix materials, with monodomain, vortex-like and multidomain patterns emerging for various combinations of size and materials parameters. This leads to radically different polarization vs. electric field responses, resulting in highly tunable size-dependent dielectric properties that should be possible to observe experimentally. Our calculations show that there is a critical particle size below which ferroelectricity vanishes. For the PbTiO3 particle, this size is 2 and 3.4 nm, respectively, for high- and low-permittivity media. For the BaTiO3 particle, it is ∼3.6 nm regardless of the medium dielectric strength.
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Affiliation(s)
- John Mangeri
- Department of Physics, University of Connecticut, Storrs, CT, USA.
| | - Yomery Espinal
- Department of Materials Science and Engineering, University of Connecticut, Storrs, CT, USA
| | - Andrea Jokisaari
- Center for Hierarchical Material Design, Northwestern-Argonne Institute of Science and Engineering, Northwestern University, Evanston, IL, USA.
| | - S Pamir Alpay
- Department of Physics, University of Connecticut, Storrs, CT, USA. and Department of Materials Science and Engineering, University of Connecticut, Storrs, CT, USA and Institute of Materials Science, University of Connecticut, Storrs, CT, USA
| | - Serge Nakhmanson
- Department of Physics, University of Connecticut, Storrs, CT, USA. and Department of Materials Science and Engineering, University of Connecticut, Storrs, CT, USA and Institute of Materials Science, University of Connecticut, Storrs, CT, USA
| | - Olle Heinonen
- Center for Hierarchical Material Design, Northwestern-Argonne Institute of Science and Engineering, Northwestern University, Evanston, IL, USA. and Material Science Division, Argonne National Laboratory, Lemont, IL, USA
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16
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Anomalous domain periodicity observed in ferroelectric PbTiO3 nanodots having 180° stripe domains. Sci Rep 2016; 6:26644. [PMID: 27226162 PMCID: PMC4880891 DOI: 10.1038/srep26644] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2016] [Accepted: 05/05/2016] [Indexed: 11/08/2022] Open
Abstract
Nanometer-scale ferroelectric dots and tubes have received a great deal of attention owing to their potential applications to nonvolatile memories and multi-functional devices. As for the size effect of 180° stripe domains in ferroelectric thin films, there have been numerous reports on the thickness-dependent domain periodicity. All these studies have revealed that the domain periodicity (w) of 180° stripe domains scales with the film thickness (d) according to the classical Landau-Lifshitz-Kittel (LLK) scaling law (w ∝ d1/2) down to the thickness of ~2 nm. In the case of PbTiO3 nanodots, however, we obtained a striking correlation that for the thickness less than a certain critical value, dc (~35 nm), the domain width even increases with decreasing thickness of the nanodot, which surprisingly indicates a negative value in the LLK scaling-law exponent. On the basis of theoretical considerations of dc, we attributed this anomalous domain periodicity to the finite lateral-size effect of a ferroelectric nanodot with an additional effect possibly coming from the existence of a thin non-ferroelectric surface layer.
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17
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Discovery of stable skyrmionic state in ferroelectric nanocomposites. Nat Commun 2015; 6:8542. [PMID: 26436432 PMCID: PMC4600738 DOI: 10.1038/ncomms9542] [Citation(s) in RCA: 68] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2015] [Accepted: 09/01/2015] [Indexed: 11/08/2022] Open
Abstract
Non-coplanar swirling field textures, or skyrmions, are now widely recognized as objects of both fundamental interest and technological relevance. So far, skyrmions were amply investigated in magnets, where due to the presence of chiral interactions, these topological objects were found to be intrinsically stabilized. Ferroelectrics on the other hand, lacking such chiral interactions, were somewhat left aside in this quest. Here we demonstrate, via the use of a first-principles-based framework, that skyrmionic configuration of polarization can be extrinsically stabilized in ferroelectric nanocomposites. The interplay between the considered confined geometry and the dipolar interaction underlying the ferroelectric phase instability induces skyrmionic configurations. The topological structure of the obtained electrical skyrmion can be mapped onto the topology of domain-wall junctions. Furthermore, the stabilized electrical skyrmion can be as small as a few nanometers, thus revealing prospective skyrmion-based applications of ferroelectric nanocomposites.
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Wu CM, Chen WJ, Zheng Y, Ma DC, Wang B, Liu JY, Woo CH. Controllability of vortex domain structure in ferroelectric nanodot: fruitful domain patterns and transformation paths. Sci Rep 2014; 4:3946. [PMID: 24492764 PMCID: PMC3912473 DOI: 10.1038/srep03946] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2013] [Accepted: 01/15/2014] [Indexed: 11/09/2022] Open
Abstract
Ferroelectric vortex domain structure which exists in low-dimensional ferroelectrics is being intensively researched for future applications in functional nanodevices. Here we demonstrate that adjusting surface charge screening in combination with temperature can provide an efficient way to gain control of vortex domain structure in ferroelectric nanodot. Systematical simulating experiments have been conducted to reveal the stability and evolution mechanisms of domain structure in ferroelectric nanodot under various conditions, including processes of cooling-down/heating-up under different surface charge screening conditions, and increasing/decreasing surface charge screening at different temperatures. Fruitful phase diagrams as functions of surface screening and temperature are presented, together with evolution paths of various domain patterns. Calculations discover up to 25 different kinds of domain patterns and 22 typical evolution paths of phase transitions. The fruitful controllability of vortex domain structure by surface charge screening in combination with temperature should shed light on prospective nanodevice applications of low-dimensional ferroelectric nanostructures.
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Affiliation(s)
- C M Wu
- State Key Laboratory of Optoelectronic Materials and Technologies, Micro&Nano Physics and Mechanics Research Laboratory, School of Physics and Engineering, Sun Yat-sen University, Guangzhou 510275, China
| | - W J Chen
- State Key Laboratory of Optoelectronic Materials and Technologies, Micro&Nano Physics and Mechanics Research Laboratory, School of Physics and Engineering, Sun Yat-sen University, Guangzhou 510275, China
| | - Yue Zheng
- 1] State Key Laboratory of Optoelectronic Materials and Technologies, Micro&Nano Physics and Mechanics Research Laboratory, School of Physics and Engineering, Sun Yat-sen University, Guangzhou 510275, China [2] Department of Physics and Materials Science, City University of Hong Kong, Hong Kong SAR, China
| | - D C Ma
- Sino-French Institute of Nuclear Engineering and Technology, Zhuhai Campus, Sun Yat-sen University, Zhuhai 519082, China
| | - B Wang
- State Key Laboratory of Optoelectronic Materials and Technologies, Micro&Nano Physics and Mechanics Research Laboratory, School of Physics and Engineering, Sun Yat-sen University, Guangzhou 510275, China
| | - J Y Liu
- State Key Laboratory of Optoelectronic Materials and Technologies, Micro&Nano Physics and Mechanics Research Laboratory, School of Physics and Engineering, Sun Yat-sen University, Guangzhou 510275, China
| | - C H Woo
- Department of Physics and Materials Science, City University of Hong Kong, Hong Kong SAR, China
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Ahluwalia R, Ng N, Schilling A, McQuaid RGP, Evans DM, Gregg JM, Srolovitz DJ, Scott JF. Manipulating ferroelectric domains in nanostructures under electron beams. PHYSICAL REVIEW LETTERS 2013; 111:165702. [PMID: 24182281 DOI: 10.1103/physrevlett.111.165702] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2013] [Indexed: 06/02/2023]
Abstract
Freestanding BaTiO3 nanodots exhibit domain structures characterized by distinct quadrants of ferroelastic 90° domains in transmission electron microscopy (TEM) observations. These differ significantly from flux-closure domain patterns in the same systems imaged by piezoresponse force microscopy. Based upon a series of phase field simulations of BaTiO3 nanodots, we suggest that the TEM patterns result from a radial electric field arising from electron beam charging of the nanodot. For sufficiently large charging, this converts flux-closure domain patterns to quadrant patterns with radial net polarizations. Not only does this explain the puzzling patterns that have been observed in TEM studies of ferroelectric nanodots, but also suggests how to manipulate ferroelectric domain patterns via electron beams.
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Affiliation(s)
- R Ahluwalia
- Institute of High Performance Computing, Singapore 138632, Singapore
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Chen WJ, Zheng Y, Wang B, Ma DC, Ling FR. Vortex domain structures of an epitaxial ferroelectric nanodot and its temperature-misfit strain phase diagram. Phys Chem Chem Phys 2013; 15:7277-85. [DOI: 10.1039/c3cp00133d] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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21
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Vortex domain structure in ferroelectric nanoplatelets and control of its transformation by mechanical load. Sci Rep 2012; 2:796. [PMID: 23150769 PMCID: PMC3495285 DOI: 10.1038/srep00796] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2012] [Accepted: 10/09/2012] [Indexed: 11/08/2022] Open
Abstract
Vortex domain patterns in low-dimensional ferroelectrics and multiferroics have been extensively studied with the aim of developing nanoscale functional devices. However, control of the vortex domain structure has not been investigated systematically. Taking into account effects of inhomogeneous electromechanical fields, ambient temperature, surface and size, we demonstrate significant influence of mechanical load on the vortex domain structure in ferroelectric nanoplatelets. Our analysis shows that the size and number of dipole vortices can be controlled by mechanical load, and yields rich temperature-stress (T-S) phase diagrams. Simulations also reveal that transformations between “vortex states” induced by the mechanical load are possible, which is totally different from the conventional way controlled on the vortex domain by the electric field. These results are relevant to application of vortex domain structures in ferroelectric nanodevices, and suggest a novel route to applications including memories, mechanical sensors and transducers.
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Stachiotti MG, Sepliarsky M. Toroidal ferroelectricity in PbTiO3 nanoparticles. PHYSICAL REVIEW LETTERS 2011; 106:137601. [PMID: 21517419 DOI: 10.1103/physrevlett.106.137601] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2010] [Indexed: 05/30/2023]
Abstract
We report from first-principles-based atomistic simulations that ferroelectricity can be sustained in PbTiO(3) nanoparticles of only a few lattice constants in size as a result of a toroidal ordering. We find that size-induced topological transformations lead to the stabilization of a ferroelectric bubble by the alignment of vortex cores along a closed path. These transformations, which are driven by the aspect ratio of the nanostructure, change the topology of the polarization field, producing a rich variety of polar configurations. For sufficiently flat nanostructures, a multibubble state bridges the gap between 0D nanodots and 2D ultrathin films. The thermal properties of the ferroelectric bubbles indicate that this state is suitable for the development of nanometric devices.
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Affiliation(s)
- M G Stachiotti
- Instituto de Física Rosario, Universidad Nacional de Rosario, 27 de Febrero 210 Bis, (2000) Rosario, Argentina
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Jia CL, Urban KW, Alexe M, Hesse D, Vrejoiu I. Direct Observation of Continuous Electric Dipole Rotation in Flux-Closure Domains in Ferroelectric Pb(Zr,Ti)O3. Science 2011; 331:1420-3. [DOI: 10.1126/science.1200605] [Citation(s) in RCA: 340] [Impact Index Per Article: 26.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
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Nakhmanson SM, Naumov I. Goldstone-like states in a layered perovskite with frustrated polarization: a first-principles investigation of PbSr2Ti2O7. PHYSICAL REVIEW LETTERS 2010; 104:097601. [PMID: 20367010 DOI: 10.1103/physrevlett.104.097601] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/23/2009] [Indexed: 05/29/2023]
Abstract
With the help of first-principles-based computational techniques, we demonstrate that Goldstone-like states can be artificially induced in a layered-perovskite ferroelectric compound with frustrated polarization, resulting in the emergence of a variety of interesting physical properties that include large, tunable dielectric constants and an ability to easily form vortex polar states in a nanodot geometry. In a similar fashion to the well-known perovskite materials with morphotropic phase boundaries (MPBs), these states manifest themselves as polarization rotations with almost no energy penalty, suggesting that the existence of an MPB is actually yet another manifestation of the Goldstone theorem in solids.
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Affiliation(s)
- S M Nakhmanson
- Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439, USA
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Trepakov VA, Potůček Z, Makarova MV, Dejneka A, Sazama P, Jastrabik L, Bryknar Z. SrTiO(3):Cr nanocrystalline powders: size effects and optical properties. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2009; 21:375303. [PMID: 21832345 DOI: 10.1088/0953-8984/21/37/375303] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
The crystal structure, optical absorption, and photoluminescence of chromium impurity centers were studied in nanocrystalline SrTiO(3):Cr (0.1 mol%) powders with average particle size within the range 13-100 nm prepared by the Pechini-type polymeric sol-gel method. Only the presence of a cubic perovskite phase of O(h)(1) symmetry was proved for the powders at room temperature, by means of x-ray diffraction. The lattice constant a = 3.910 Å, larger than that of bulk SrTiO(3) crystals (a = 3.905 Å), was found for nanoparticles with the size about 20 nm. The optical absorption edge and the zero-phonon R-line ([Formula: see text]) of luminescence of the octahedral Cr(3+) centers shifted to higher energies with decreasing nanoparticle size. These size effects were regarded as intrinsic to SrTiO(3). An unusual and large temperature shift of the R-line position very similar to the 'dielectric related' one of the bulk crystals was observed for all powders, evidencing their quantum paraelectric behavior. However, the powders with the average particle size about 13 and 20 nm did not reveal completely reproducible behavior of the R-line position at low temperatures. This instability was considered a possible manifestation of a low-temperature phase transition in small enough SrTiO(3) nanoparticles.
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Affiliation(s)
- V A Trepakov
- Institute of Physics ASCR, v. v. i., Na Slovance 2, CZ-182 21 Praha 8, Czech Republic. A F Ioffe Physico-Technical Institute RAS, 194 021, Saint Petersburg, Russia
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Rodriguez BJ, Gao XS, Liu LF, Lee W, Naumov II, Bratkovsky AM, Hesse D, Alexe M. Vortex polarization states in nanoscale ferroelectric arrays. NANO LETTERS 2009; 9:1127-1131. [PMID: 19191502 DOI: 10.1021/nl8036646] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Two-dimensional arrays of ferroelectric lead zirconate titanate (PZT) nanodots were fabricated using pulsed laser deposition through ultrathin anodic aluminum oxide membrane stencil masks. The static distribution of polarization configurations was investigated using in- and out-of-plane piezoresponse force microscopy (PFM). The observed presence of an in-plane polarization component in nominally (001) oriented PZT suggests the existence of a significant deviation from the regular tetragonal structure that allows the formation of complex core-polarization states. Core-polarization states may indicate the presence of quasi-toroidal polarization ordering. The experimental results are compared with a theoretical model to determine the fingerprint of a vortex polarization state in PFM.
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Affiliation(s)
- B J Rodriguez
- Max Planck Institute of Microstructure Physics, Weinberg 2, D-06120 Halle, Germany
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