101
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Yang MM, Iqbal AN, Peters JJP, Sanchez AM, Alexe M. Strain-gradient mediated local conduction in strained bismuth ferrite films. Nat Commun 2019; 10:2791. [PMID: 31243266 PMCID: PMC6594973 DOI: 10.1038/s41467-019-10664-5] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2018] [Accepted: 05/15/2019] [Indexed: 11/27/2022] Open
Abstract
It has been recently shown that the strain gradient is able to separate the light-excited electron-hole pairs in semiconductors, but how it affects the photoelectric properties of the photo-active materials remains an open question. Here, we demonstrate the critical role of the strain gradient in mediating local photoelectric properties in the strained BiFeO3 thin films by systematically characterizing the local conduction with nanometre lateral resolution in both dark and illuminated conditions. Due to the giant strain gradient manifested at the morphotropic phase boundaries, the associated flexo-photovoltaic effect induces on one side an enhanced photoconduction in the R-phase, and on the other side a negative photoconductivity in the morphotropic \documentclass[12pt]{minimal}
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\begin{document}$$T\prime$$\end{document}T′-phase. This work offers insight and implication of the strain gradient on the electronic properties in both optoelectronic and photovoltaic devices. In semiconductors strain gradients can separate light induced electron-hole pairs via the flexo-photovoltaic effect. Here the authors show that this effect can also account for the enhancement of the photoconduction in certain phase regions at the morphotropic phase boundary in Bismuth Ferrite films.
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Affiliation(s)
- Ming-Min Yang
- Department of Physics, The University of Warwick, Coventry, CV4 7AL, UK.
| | - Affan N Iqbal
- Department of Physics, The University of Warwick, Coventry, CV4 7AL, UK
| | | | - Ana M Sanchez
- Department of Physics, The University of Warwick, Coventry, CV4 7AL, UK
| | - Marin Alexe
- Department of Physics, The University of Warwick, Coventry, CV4 7AL, UK.
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102
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Liou YD, Chiu YY, Hart RT, Kuo CY, Huang YL, Wu YC, Chopdekar RV, Liu HJ, Tanaka A, Chen CT, Chang CF, Tjeng LH, Cao Y, Nagarajan V, Chu YH, Chen YC, Yang JC. Deterministic optical control of room temperature multiferroicity in BiFeO 3 thin films. NATURE MATERIALS 2019; 18:580-587. [PMID: 31061484 DOI: 10.1038/s41563-019-0348-x] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/14/2018] [Accepted: 03/15/2019] [Indexed: 05/12/2023]
Abstract
Controlling ferroic orders (ferroelectricity, ferromagnetism and ferroelasticity) by optical methods is a significant challenge due to the large mismatch in energy scales between the order parameter coupling strengths and the incident photons. Here, we demonstrate an approach to manipulate multiple ferroic orders in an epitaxial mixed-phase BiFeO3 thin film at ambient temperature via laser illumination. Phase-field simulations indicate that a light-driven flexoelectric effect allows the targeted formation of ordered domains. We also achieved precise sequential laser writing and erasure of different domain patterns, which demonstrates a deterministic optical control of multiferroicity at room temperature. As ferroic orders directly influence susceptibility and conductivity in complex materials, our results not only shed light on the optical control of multiple functionalities, but also suggest possible developments for optoelectronics and related applications.
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Affiliation(s)
- Yi-De Liou
- Department of Physics, National Cheng Kung University, Tainan, Taiwan
| | - Yu-You Chiu
- Department of Physics, National Cheng Kung University, Tainan, Taiwan
| | - Ryan Thomas Hart
- Department of Materials Science and Engineering, University of Texas at Arlington, Arlington, TX, USA
| | - Chang-Yang Kuo
- Max-Planck Institute for Chemical Physics of Solids, Dresden, Germany
- National Synchrotron Radiation Research Center, Hsinchu, Taiwan
| | - Yen-Lin Huang
- Department of Materials Science and Engineering, National Chiao Tung University, Hsinchu, Taiwan
| | - Yuan-Chih Wu
- Department of Physics, National Cheng Kung University, Tainan, Taiwan
| | - Rajesh V Chopdekar
- Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Heng-Jui Liu
- Department of Materials Science and Engineering, National Chung Hsing University, Taichung, Taiwan
| | - Arata Tanaka
- Department of Quantum Matter, ADSM, Hiroshima University, Higashi-Hiroshima, Japan
| | - Chien-Te Chen
- National Synchrotron Radiation Research Center, Hsinchu, Taiwan
| | - Chun-Fu Chang
- Max-Planck Institute for Chemical Physics of Solids, Dresden, Germany
| | - Liu Hao Tjeng
- Max-Planck Institute for Chemical Physics of Solids, Dresden, Germany
| | - Ye Cao
- Department of Materials Science and Engineering, University of Texas at Arlington, Arlington, TX, USA
| | - Valanoor Nagarajan
- School of Materials Science and Engineering, University of New South Wales, Sydney, New South Wales, Australia
| | - Ying-Hao Chu
- Department of Materials Science and Engineering, National Chiao Tung University, Hsinchu, Taiwan
- Center for Emergent Functional Matter Science, National Chiao Tung University, Hsinchu, Taiwan
- Institute of Physics, Academia Sinica, Taipei, Taiwan
| | - Yi-Chun Chen
- Department of Physics, National Cheng Kung University, Tainan, Taiwan.
- Center for Quantum Frontiers of Research & Technology (QFort), National Cheng Kung University, Tainan, Taiwan.
| | - Jan-Chi Yang
- Department of Physics, National Cheng Kung University, Tainan, Taiwan.
- Center for Quantum Frontiers of Research & Technology (QFort), National Cheng Kung University, Tainan, Taiwan.
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103
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Gerrard N, Gattinoni C, McBride F, Michaelides A, Hodgson A. Strain Relief during Ice Growth on a Hexagonal Template. J Am Chem Soc 2019; 141:8599-8607. [PMID: 31023010 PMCID: PMC6543506 DOI: 10.1021/jacs.9b03311] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2019] [Indexed: 12/16/2022]
Abstract
Heterogeneous ice nucleation at solid surfaces impacts many areas of science, from environmental processes, such as precipitation, to microbiological systems and food processing, but the microscopic mechanisms underpinning nucleation remain unclear. Discussion of ice growth has often focused around the role of the surface in templating the structure of water, forcing the first layer to adopt the registry of the underlying substrate rather than that of ice. To grow a thick ice film, water in the first few ice layers must accommodate this strain, but understanding how this occurs requires detailed molecular-scale information that is lacking. Here we combine scanning tunneling microscopy, low-energy electron diffraction, and work-function measurements with electronic structure calculations to investigate the initial stages of ice growth on a Pt alloy surface, having a lattice spacing 6% larger than ice. Although the first layer of water forms a strictly commensurate hexagonal network, this behavior does not extend to the second layer. Instead, water forms a 2D structure containing extended defect rows made from face-sharing pentamer and octamer rings. The defect rows allow the majority of second-layer water to remain commensurate with the solid surface while compensating lateral strain by increasing the water density close to that of an ice surface. The observation of octamer-pentamer rows in ice films formed on several surfaces suggests that the octamer-pentamer defect motif acts as a flexible strain relief mechanism in thin ice films, providing a mechanism that is not available during the growth of strained films in other materials, such as semiconductors.
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Affiliation(s)
- Nikki Gerrard
- Surface
Science Research Centre and Department of Chemistry, University of Liverpool, Liverpool L69 3BX, United Kingdom
| | - Chiara Gattinoni
- Materials
Theory, ETH Zürich, Wolfgang-Pauli-Str. 27, 8093 Zürich, Switzerland
| | - Fiona McBride
- Surface
Science Research Centre and Department of Chemistry, University of Liverpool, Liverpool L69 3BX, United Kingdom
| | - Angelos Michaelides
- Thomas
Young Centre, London Centre for Nanotechnology and Department of Physics
and Astronomy, University College London, London WC1E 6BT, United Kingdom
| | - Andrew Hodgson
- Surface
Science Research Centre and Department of Chemistry, University of Liverpool, Liverpool L69 3BX, United Kingdom
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104
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Short range biaxial strain relief mechanism within epitaxially grown BiFeO 3. Sci Rep 2019; 9:6715. [PMID: 31040305 PMCID: PMC6491549 DOI: 10.1038/s41598-019-42998-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2019] [Accepted: 04/10/2019] [Indexed: 11/30/2022] Open
Abstract
Lattice mismatch-induced biaxial strain effect on the crystal structure and growth mechanism is investigated for the BiFeO3 films grown on La0.6Sr0.4MnO3/SrTiO3 and YAlO3 substrates. Nano-beam electron diffraction, structure factor calculation and x-ray reciprocal space mapping unambiguously confirm that the crystal structure within both of the BiFeO3 thin films is rhombohedral by showing the rhombohedral signature Bragg’s reflections. Further investigation with atomic resolution scanning transmission electron microscopy reveals that while the ~1.0% of the lattice mismatch found in the BiFeO3 grown on La0.6Sr0.4MnO3/SrTiO3 is exerted as biaxial in-plane compressive strain with atomistically coherent interface, the ~6.8% of the lattice mismatch found in the BiFeO3 grown on YAlO3 is relaxed at the interface by introducing dislocations. The present result demonstrates the importance of: (1) identification of the epitaxial relationship between BFO and its substrate material to quantitatively evaluate the amount of the lattice strain within BFO film and (2) the atomistically coherent BFO/substrate interface for the lattice mismatch to exert the lattice strain.
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105
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Chen C, Wang C, Cai X, Xu C, Li C, Zhou J, Luo Z, Fan Z, Qin M, Zeng M, Lu X, Gao X, Kentsch U, Yang P, Zhou G, Wang N, Zhu Y, Zhou S, Chen D, Liu JM. Controllable defect driven symmetry change and domain structure evolution in BiFeO 3 with enhanced tetragonality. NANOSCALE 2019; 11:8110-8118. [PMID: 30984948 DOI: 10.1039/c9nr00932a] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Defect engineering has been a powerful tool to enable the creation of exotic phases and the discovery of intriguing phenomena in ferroelectric oxides. However, the accurate control of the concentration of defects remains a big challenge. In this work, ion implantation, which can provide controllable point defects, allows us to produce a controlled defect driven true super-tetragonal (T) phase with a single-domain-state in ferroelectric BiFeO3 thin films. This point-defect engineering is found to drive the phase transition from the as-grown mixed rhombohedral-like (R) and tetragonal-like (MC) phase to true tetragonal (T) symmetry and induce the stripe multi-nanodomains to a single domain state. By further increasing the injected dose of the He ion, we demonstrate an enhanced tetragonality super-tetragonal (super-T) phase with the largest c/a ratio of ∼1.3 that has ever been experimentally achieved in BiFeO3. A combination of the morphology change and domain evolution further confirms that the mixed R/MC phase structure transforms to the single-domain-state true tetragonal phase. Moreover, the re-emergence of the R phase and in-plane nanoscale multi-domains after heat treatment reveal the memory effect and reversible phase transition and domain evolution. Our findings demonstrate the reversible control of R-Mc-T-super T symmetry changes (leading to the creation of true T phase BiFeO3 with enhanced tetragonality) and multidomain-single domain structure evolution through controllable defect engineering. This work also provides a pathway to generate large tetragonality (or c/a ratio) that could be extended to other ferroelectric material systems (such as PbTiO3, BaTiO3 and HfO2) which might lead to strong polarization enhancement.
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Affiliation(s)
- Chao Chen
- Institute for Advanced Materials, South China Academy of Advanced Optoelectronics, South China Normal University, Guangzhou 510006, China.
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106
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Mbatang R, Xue D, Enriquez E, Yuan R, Han H, Dowden P, Wang Q, Fohtung E, Xue D, Lookman T, Pennycook SJ, Chen A. Enhanced magnetism in lightly doped manganite heterostructures: strain or stoichiometry? NANOSCALE 2019; 11:7364-7370. [PMID: 30938718 DOI: 10.1039/c8nr09693g] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Lattice mismatch induced epitaxial strain has been widely used to tune functional properties in complex oxide heterostructures. Apart from the epitaxial strain, a large lattice mismatch also produces other effects including modulations in microstructure and stoichiometry. However, it is challenging to distinguish the impact of these effects from the strain contribution to thin film properties. Here, we use La0.9Sr0.1MnO3 (LSMO), a lightly doped manganite close to the vertical phase boundary, as a model system to demonstrate that both epitaxial strain and cation stoichiometry induced by strain relaxation contribute to functionality tuning. The thinner LSMO films are metallic with a greatly enhanced TC which is 97 K higher than the bulk value. Such anomalies in TC and transport cannot be fully explained by the epitaxial strain alone. Detailed microstructure analysis indicates La deficiency in thinner films and twin domain formation in thicker films. Our results have revealed that both epitaxial strain and strain relaxation induced stoichiometry/microstructure modulations contribute to the modified functional properties in lightly doped manganite perovskite thin films.
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Affiliation(s)
- Richard Mbatang
- Center for Integrated Nanotechnologies (CINT), Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA.
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107
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Yang C, Han Y, Qian J, Lv P, Lin X, Huang S, Cheng Z. Flexible, Temperature-Resistant, and Fatigue-Free Ferroelectric Memory Based on Bi(Fe 0.93Mn 0.05Ti 0.02)O 3 Thin Film. ACS APPLIED MATERIALS & INTERFACES 2019; 11:12647-12655. [PMID: 30874425 DOI: 10.1021/acsami.9b01464] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
A recent hot-spot topic for flexible and wearable devices involves high-performance nonvolatile ferroelectric memories operating under compressive or tensile mechanical deformations. This work presents the direct fabrication of a flexible (Mn,Ti)-codoped multiferroic BiFeO3 film capacitor with Pt bottom and Au top electrodes on mica substrate. The fabricated polycrystalline Bi(Fe0.93Mn0.05Ti0.02)O3 film on mica exhibits superior ferroelectric switching behavior with robust saturated polarization ( Ps ∼ 93 μC/cm2) and remanent polarization ( Pr ∼ 66 μC/cm2) and excellent frequency stability (1-50 kHz) and temperature resistance (25-200 °C), as well as reliable long-lifetime operation. More saliently, it can be safely bent to a small radius of curvature, as low as 2 mm, or go through repeated compressive/tensile mechanical flexing for 103 bending times at 4 mm radius without any obvious deterioration in polarization, retention time at 105 s, or fatigue resistance after 109 switching cycles. These findings demonstrate a novel route to designing flexible BiFeO3-based ferroelectric memories for information storage and data processing, with promising applications in next-generation smart electronics.
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Affiliation(s)
| | | | | | | | | | | | - Zhenxiang Cheng
- Institute for Superconducting and Electronic Materials, Australian Institute for Innovative Materials , University of Wollongong , Innovation Campus, North Wollongong , NSW 2500 , Australia
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108
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Simons H, Jakobsen AC, Ahl SR, Poulsen HF, Pantleon W, Chu YH, Detlefs C, Valanoor N. Nondestructive Mapping of Long-Range Dislocation Strain Fields in an Epitaxial Complex Metal Oxide. NANO LETTERS 2019; 19:1445-1450. [PMID: 30724569 DOI: 10.1021/acs.nanolett.8b03839] [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
The misfit dislocations formed at heteroepitaxial interfaces create long-ranging strain fields in addition to the epitaxial strain. For systems with strong lattice coupling, such as ferroic oxides, this results in unpredictable and potentially debilitating functionality and device performance. In this work, we use dark-field X-ray microscopy to map the lattice distortions around misfit dislocations in an epitaxial film of bismuth ferrite (BiFeO3), a well-known multiferroic. We demonstrate the ability to precisely quantify weak, long-ranging strain fields and their associated symmetry lowering without modifying the mechanical state of the film. We isolate the screw and edge components of the individual dislocations and show how they result in weak charge heterogeneities via flexoelectric coupling. We show that even systems with small lattice mismatches and additional mechanisms of stress relief (such as mechanical twinning) may still give rise to measurable charge and strain heterogeneities that extend over mesoscopic length scales. This sets more stringent physical limitations on device size, dislocation density, and the achievable degree of lattice mismatch in epitaxial systems.
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Affiliation(s)
- Hugh Simons
- Department of Physics , Technical University of Denmark , Kgs. Lyngby 2800 , Denmark
| | | | - Sonja Rosenlund Ahl
- Department of Physics , Technical University of Denmark , Kgs. Lyngby 2800 , Denmark
| | - Henning Friis Poulsen
- Department of Physics , Technical University of Denmark , Kgs. Lyngby 2800 , Denmark
| | - Wolfgang Pantleon
- Department of Mechanical Engineering , Technical University of Denmark , Kgs. Lyngby 2800 , Denmark
| | - Ying-Hao Chu
- Department of Materials Science & Engineering , National Chiao Tung University , Hsinchu 30010 , Taiwan
| | - Carsten Detlefs
- European Synchrotron Radiation Facility , 71 Avenue des Martyrs , 38043 Grenoble Cedex 9 France
| | - Nagarajan Valanoor
- School of Materials Science & Engineering , University of New South Wales , Kensington 2052 , Australia
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109
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Biswas A, Talha M, Kashir A, Jeong YH. A thin film perspective on quantum functional oxides. CURRENT APPLIED PHYSICS 2019; 19:207-214. [DOI: 10.1016/j.cap.2018.07.013] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/01/2023]
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110
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Evaluation of the Structural Phase Transition in Multiferroic (Bi1−x Prx)(Fe0.95 Mn0.05)O3 Thin Films by A Multi-Technique Approach Including Picosecond Laser Ultrasonics. APPLIED SCIENCES-BASEL 2019. [DOI: 10.3390/app9040736] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Picosecond laser ultrasonics is an experimental technique for the generation and detection of ultrashort acoustic pulses using ultrafast lasers. In transparent media, it is often referred to as time-domain Brillouin scattering (TDBS). It provides the opportunity to monitor the propagation of nanometers-length acoustic pulses and to determine acoustical, optical, and acousto-optical parameters of the materials. We report on the application of TDBS for evaluating the effect of Praseodymium (Pr) substitution on the elasticity of multiferroic (Bi1−xPrx)(Fe0.95Mn0.05)O3 (BPFMO) thin films. The films were deposited on Si and LaAlO3 (LAO) substrates by a sol-gel method. X-ray diffraction and Raman spectra revealed earlier that a phase transition from rhombohedral to tetragonal structure occurs at about 15% Pr substitution and is accompanied by the maxima of remnant magnetization and polarization. Combining TDBS with optical spectral reflectometry, scanning electron microscopy, and topographic measurements by atomic force microscopy, we found that the structural transition is also characterized by the maximum optical dielectric constant and the minimum longitudinal sound velocity. Our results, together with earlier ones, suggest that BiFeO3-based films and ceramics with compositions near phase boundaries might be promising materials for multifunctional applications.
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111
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Herklotz A, Rus SF, Balke N, Rouleau C, Guo EJ, Huon A, Kc S, Roth R, Yang X, Vaswani C, Wang J, Orth PP, Scheurer MS, Ward TZ. Designing Morphotropic Phase Composition in BiFeO 3. NANO LETTERS 2019; 19:1033-1038. [PMID: 30673240 DOI: 10.1021/acs.nanolett.8b04322] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
In classical morphotropic piezoelectric materials, rhombohedral and tetragonal phase variants can energetically compete to form a mixed phase regime with improved functional properties. While the discovery of morphotropic-like phases in multiferroic BiFeO3 films has broadened this definition, accessing these phase spaces is still typically accomplished through isovalent substitution or heteroepitaxial strain which do not allow for continuous modification of phase composition postsynthesis. Here, we show that it is possible to use low-energy helium implantation to tailor morphotropic phases of epitaxial BiFeO3 films postsynthesis in a continuous and iterative manner. Applying this strain doping approach to morphotropic films creates a new phase space based on internal and external lattice stress that can be seen as an analogue to temperature-composition phase diagrams of classical morphotropic ferroelectric systems.
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Affiliation(s)
- Andreas Herklotz
- Materials Science and Technology Division , Oak Ridge National Laboratory , Oak Ridge , Tennessee 37831 , United States
- Institute of Physics , Martin Luther University of Halle-Wittenberg , Halle 06099 , Germany
| | - Stefania F Rus
- Renewable Energies - Photovoltaics Laboratory , National Institute for Research and Development in Electrochemistry and Condensed Matter , Timisoara 300569 , Romania
| | - Nina Balke
- Center for Nanophase Materials Sciences , Oak Ridge National Laboratory , Oak Ridge , Tennessee 37831 , United States
| | - Christopher Rouleau
- Center for Nanophase Materials Sciences , Oak Ridge National Laboratory , Oak Ridge , Tennessee 37831 , United States
| | - Er-Jia Guo
- Neutron Scattering Division , Oak Ridge National Laboratory , Oak Ridge , Tennessee 37831 , United States
| | - Amanda Huon
- Materials Science and Technology Division , Oak Ridge National Laboratory , Oak Ridge , Tennessee 37831 , United States
- Department of Materials Science and Engineering , Drexel University , Philadelphia , Pennsylvania 19104 , United States
| | - Santosh Kc
- Materials Science and Technology Division , Oak Ridge National Laboratory , Oak Ridge , Tennessee 37831 , United States
| | - Robert Roth
- Institute of Physics , Martin Luther University of Halle-Wittenberg , Halle 06099 , Germany
| | - Xu Yang
- Department of Physics and Astronomy and Ames Laboratory-U.S. DOE , Iowa State University , Ames , Iowa 50011 , United States
| | - Chirag Vaswani
- Department of Physics and Astronomy and Ames Laboratory-U.S. DOE , Iowa State University , Ames , Iowa 50011 , United States
| | - Jigang Wang
- Department of Physics and Astronomy and Ames Laboratory-U.S. DOE , Iowa State University , Ames , Iowa 50011 , United States
| | - Peter P Orth
- Department of Physics and Astronomy and Ames Laboratory-U.S. DOE , Iowa State University , Ames , Iowa 50011 , United States
| | - Mathias S Scheurer
- Department of Physics , Harvard University , Cambridge , Massachusetts 02138 , United States
| | - Thomas Z Ward
- Materials Science and Technology Division , Oak Ridge National Laboratory , Oak Ridge , Tennessee 37831 , United States
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112
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Pandya S, Velarde GA, Gao R, Everhardt AS, Wilbur JD, Xu R, Maher JT, Agar JC, Dames C, Martin LW. Understanding the Role of Ferroelastic Domains on the Pyroelectric and Electrocaloric Effects in Ferroelectric Thin Films. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2019; 31:e1803312. [PMID: 30515861 DOI: 10.1002/adma.201803312] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/24/2018] [Revised: 10/23/2018] [Indexed: 05/17/2023]
Abstract
Temperature- and electric-field-induced structural transitions in a polydomain ferroelectric can have profound effects on its electrothermal susceptibilities. Here, the role of such ferroelastic domains on the pyroelectric and electrocaloric response is experimentally investigated in thin films of the tetragonal ferroelectric PbZr0.2 Ti0.8 O3 . By utilizing epitaxial strain, a rich set of ferroelastic polydomain states spanning a broad thermodynamic phase space are stabilized. Using temperature-dependent scanning-probe microscopy, X-ray diffraction, and high-frequency phase-sensitive pyroelectric measurements, the propensity of domains to reconfigure under a temperature perturbation is quantitatively studied. In turn, the "extrinsic" contributions to pyroelectricity exclusively due to changes between the ferroelastic domain population is elucidated as a function of epitaxial strain. Further, using highly sensitive thin-film resistive thermometry, direct electrocaloric temperature changes are measured on these polydomain thin films for the first time. The results demonstrate that temperature- and electric-field-driven domain interconversion under compressive strain diminish both the pyroelectric and the electrocaloric effects, while both these susceptibilities are enhanced due to the exact-opposite effect from the extrinsic contributions under tensile strain.
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Affiliation(s)
- Shishir Pandya
- Department of Materials Science and Engineering, University of California, Berkeley, CA, 94720, USA
| | - Gabriel A Velarde
- Department of Materials Science and Engineering, University of California, Berkeley, CA, 94720, USA
| | - Ran Gao
- Department of Materials Science and Engineering, University of California, Berkeley, CA, 94720, USA
| | - Arnoud S Everhardt
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Joshua D Wilbur
- Department of Mechanical Engineering, University of California, Berkeley, CA, 94720, USA
| | - Ruijuan Xu
- Department of Materials Science and Engineering, University of California, Berkeley, CA, 94720, USA
| | - Josh T Maher
- Department of Materials Science and Engineering, University of California, Berkeley, CA, 94720, USA
| | - Joshua C Agar
- Department of Materials Science and Engineering, University of California, Berkeley, CA, 94720, USA
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Chris Dames
- Department of Mechanical Engineering, University of California, Berkeley, CA, 94720, USA
| | - 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
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113
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Tian S, Wang C, Zhou Y, Li X, Gao P, Wang J, Feng Y, Yao X, Ge C, He M, Bai X, Yang G, Jin K. Manipulating the Ferroelectric Domain States and Structural Distortion in Epitaxial BiFeO 3 Ultrathin Films via Bi Nonstoichiometry. ACS APPLIED MATERIALS & INTERFACES 2018; 10:43792-43801. [PMID: 30474948 DOI: 10.1021/acsami.8b15703] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Exploring and manipulating domain configurations in ferroelectric thin films are of critical importance for the design and fabrication of ferroelectric heterostructures with a novel functional performance. In this study, BiFeO3 (BFO) ultrathin films with various Bi/Fe ratios from excess Bi to deficient Bi have been grown on (La0.7Sr0.3)MnO3 (LSMO)-covered SrTiO3 substrates by a laser molecular beam epitaxy system. Atomic force microscopy and piezoresponse force microscopy measurements show that both the surface morphology and ferroelectric polarization of the films are relevant to Bi nonstoichiometry. More significantly, a Bi-excess thin film shows an upward (from substrate to film surface) uniform ferroelectric polarization, whereas a Bi-deficient thin film exhibits a downward uniform polarization, which means the as-grown polarization of BFO thin films can be controlled by changing the Bi contents. Atomic-scale structural and chemical characterizations and second-harmonic generation measurements reveal that two different kinds of structural distortions and interface atomic configurations in the BFO/LSMO heterostructures can be induced by the change of Bi nonstoichiometry, leading to the two opposite as-grown ferroelectric polarizations. It has also been revealed that the band gap of BFO thin films can be modulated via Bi nonstoichiometry. These results demonstrate that Bi nonstoichiometry plays a key role on the ferroelectric domain states and physical properties of BFO thin films and also open a new avenue to manipulate the structure and ferroelectric domain states in BFO thin films.
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Affiliation(s)
- Shilu Tian
- Institute of Physics , Chinese Academy of Sciences , Beijing 100190 , China
- University of Chinese Academy of Sciences , Beijing 100049 , China
| | - Can Wang
- Institute of Physics , Chinese Academy of Sciences , Beijing 100190 , China
- University of Chinese Academy of Sciences , Beijing 100049 , China
- Songshan Lake Materials Laboratory , Dongguan , Guangdong 523808 , China
| | - Yong Zhou
- Institute of Physics , Chinese Academy of Sciences , Beijing 100190 , China
- University of Chinese Academy of Sciences , Beijing 100049 , China
| | - Xiaomei Li
- Institute of Physics , Chinese Academy of Sciences , Beijing 100190 , China
- University of Chinese Academy of Sciences , Beijing 100049 , China
| | - Peng Gao
- International Center for Quantum Materials and Electron Microscopy Laboratory, School of Physics , Peking University , Beijing 100871 , China
| | - Jiesu Wang
- Institute of Physics , Chinese Academy of Sciences , Beijing 100190 , China
| | - Yu Feng
- Institute of Physics , Chinese Academy of Sciences , Beijing 100190 , China
| | - Xiaokang Yao
- Institute of Physics , Chinese Academy of Sciences , Beijing 100190 , China
- University of Chinese Academy of Sciences , Beijing 100049 , China
| | - Chen Ge
- Institute of Physics , Chinese Academy of Sciences , Beijing 100190 , China
| | - Meng He
- Institute of Physics , Chinese Academy of Sciences , Beijing 100190 , China
| | - Xuedong Bai
- Institute of Physics , Chinese Academy of Sciences , Beijing 100190 , China
- University of Chinese Academy of Sciences , Beijing 100049 , China
| | - Guozhen Yang
- Institute of Physics , Chinese Academy of Sciences , Beijing 100190 , China
- University of Chinese Academy of Sciences , Beijing 100049 , China
| | - Kuijuan Jin
- Institute of Physics , Chinese Academy of Sciences , Beijing 100190 , China
- University of Chinese Academy of Sciences , Beijing 100049 , China
- Songshan Lake Materials Laboratory , Dongguan , Guangdong 523808 , China
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114
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Park MH, Lee YH, Kim HJ, Kim YJ, Moon T, Kim KD, Hyun SD, Hwang CS. Morphotropic Phase Boundary of Hf 1- xZr xO 2 Thin Films for Dynamic Random Access Memories. ACS APPLIED MATERIALS & INTERFACES 2018; 10:42666-42673. [PMID: 30468068 DOI: 10.1021/acsami.8b15576] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
The utilization of the morphotropic phase boundary (MPB) between the newly found ferroelectric orthorhombic phase and the tetragonal phase in an HfO2-ZrO2 solid solution is suggested for a high-capacitance dielectric capacitor. Being different from other high- k dielectrics, where the k value decreases with decreasing film thickness, these films (Hf/Zr ratio = 6:4, 5:5, 3:7) showed increasing k values with decreasing film thicknesses in the ∼5-20 nm range. Among them, Hf0.5Zr0.5O2 and Hf0.3Zr0.7O2 films showed 47 and 43 peak k values at 6.5 and 9.2 nm thicknesses, respectively, suggesting the involvement of the MPB phenomenon. For the systematic understanding of this peculiar phenomenon, the phase evolution of the HfO2-ZrO2 solid solution is presented based on experimental observations. The detailed electrical tests of the films with different compositions and thicknesses demonstrated that the characteristic feature of this material system is consistent with the involvement of the MPB depending on the composition and thickness. Through the optimization of the annealing process for crystallization, a 0.62 nm minimum equivalent oxide thickness was reported for the 6.5 nm thick Hf0.5Zr0.5O2 film, which is highly promising for the future dynamic random access memories. This work provided a breakthrough method for overcoming the fundamental limitation of a decreasing k value with a decreasing film thickness of other high- k dielectrics.
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Affiliation(s)
- Min Hyuk Park
- School of Materials Science and Engineering, College of Engineering , Pusan National University , 2 Busandaehak-ro, 63 Beon-gil, Geumjeong-gu , Busan 46241 , Republic of Korea
| | - Young Hwan Lee
- Department of Materials Science and Engineering and Inter-University Semiconductor Research Center, College of Engineering , Seoul National University , Seoul 151-744 , Republic of Korea
| | - Han Joon Kim
- Department of Materials Science and Engineering and Inter-University Semiconductor Research Center, College of Engineering , Seoul National University , Seoul 151-744 , Republic of Korea
| | - Yu Jin Kim
- Department of Materials Science and Engineering and Inter-University Semiconductor Research Center, College of Engineering , Seoul National University , Seoul 151-744 , Republic of Korea
| | - Taehwan Moon
- Department of Materials Science and Engineering and Inter-University Semiconductor Research Center, College of Engineering , Seoul National University , Seoul 151-744 , Republic of Korea
| | - Keum Do Kim
- Department of Materials Science and Engineering and Inter-University Semiconductor Research Center, College of Engineering , Seoul National University , Seoul 151-744 , Republic of Korea
| | - Seung Dam Hyun
- Department of Materials Science and Engineering and Inter-University Semiconductor Research Center, College of Engineering , Seoul National University , Seoul 151-744 , Republic of Korea
| | - Cheol Seong Hwang
- Department of Materials Science and Engineering and Inter-University Semiconductor Research Center, College of Engineering , Seoul National University , Seoul 151-744 , Republic of Korea
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115
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Chu K, Yang CH. High-resolution angle-resolved lateral piezoresponse force microscopy: Visualization of in-plane piezoresponse vectors. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2018; 89:123704. [PMID: 30599567 DOI: 10.1063/1.5052662] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/20/2018] [Accepted: 11/12/2018] [Indexed: 06/09/2023]
Abstract
Piezoresponse force microscopy (PFM) is a widely used tool for ferroelectric domain imaging. Lateral PFM (LPFM) utilizes the torsional vibration mode of a probe cantilever; it can distinguish ferroelectric domains having different polarizations with respect to the axis perpendicular to the cantilever, but it is blind to the parallel axis innately. We introduce a high-resolution angle-resolved-LPFM technique that is capable of visualizing full two-dimensional in-plane piezoresponse vector fields. The LPFM signal is analyzed for each pixel with respect to the sample-probe orientation angle with the aid of an image registration technique, and the corresponding local in-plane piezoresponse vector is deduced from the amplitude and phase of the trigonometric curve fitting. This technique provides a pathway for the visualization of complicated ferroelectric and piezoelectric structures.
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Affiliation(s)
- Kanghyun Chu
- Department of Physics, KAIST, Daejeon 34141, South Korea
| | - Chan-Ho Yang
- Department of Physics, KAIST, Daejeon 34141, South Korea
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116
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Geng W, Guo X, Zhu Y, Tang Y, Feng Y, Zou M, Wang Y, Han M, Ma J, Wu B, Hu W, Ma X. Rhombohedral-Orthorhombic Ferroelectric Morphotropic Phase Boundary Associated with a Polar Vortex in BiFeO 3 Films. ACS NANO 2018; 12:11098-11105. [PMID: 30352155 DOI: 10.1021/acsnano.8b05449] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Strongly correlated oxides exhibit multiple degrees of freedoms, which can potentially mediate exotic phases with exciting physical properties, such as the polar vortex recently found in ferroelectric oxide films. A polar vortex is stabilized by competition between charge, lattice, and/or orbital degrees of freedom, which displays vortex-ferroelectric phase transitions and emergent chirality, making it a potential candidate for designing information storage and processing devices. Here, by a combination of controlled film growth and aberration-corrected scanning transmission electron microscopy, we obtain nanoscale vortex arrays in [110]-oriented BiFeO3 films. These vortex arrays are stabilized in ultrathin BiFeO3 layers sandwiched by two coherently grown orthorhombic scandate layers, exhibiting a ferroelectric morphotropic phase boundary constituted by a mixed-phase structure of polar orthorhombic BiFeO3 and rhombohedral BiFeO3. Clear polarization switching and piezoelectric signals were observed in these multilayers as revealed by piezoresponse force microscopy. This work presents a feature of a polar vortex in BiFeO3 films showing morphotropic phase boundary character, which offers a potential degree of manipulating phase components and properties of ferroelectric topological structures.
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Affiliation(s)
- Wanrong Geng
- Shenyang National Laboratory for Materials Science , Institute of Metal Research, Chinese Academy of Sciences , Wenhua Road 72 , 110016 Shenyang , China
- University of Science and Technology of China , Jinzhai Road 96 , 230026 Hefei , China
| | - Xiangwei Guo
- Shenyang National Laboratory for Materials Science , Institute of Metal Research, Chinese Academy of Sciences , Wenhua Road 72 , 110016 Shenyang , China
- University of Science and Technology of China , Jinzhai Road 96 , 230026 Hefei , China
| | - Yinlian Zhu
- Shenyang National Laboratory for Materials Science , Institute of Metal Research, Chinese Academy of Sciences , Wenhua Road 72 , 110016 Shenyang , China
| | - Yunlong Tang
- Shenyang National Laboratory for Materials Science , Institute of Metal Research, Chinese Academy of Sciences , Wenhua Road 72 , 110016 Shenyang , China
| | - Yanpeng Feng
- Shenyang National Laboratory for Materials Science , Institute of Metal Research, Chinese Academy of Sciences , Wenhua Road 72 , 110016 Shenyang , China
- University of Chinese Academy of Sciences , Yuquan Road 19 , 100049 Beijing , China
| | - Minjie Zou
- Shenyang National Laboratory for Materials Science , Institute of Metal Research, Chinese Academy of Sciences , Wenhua Road 72 , 110016 Shenyang , China
- University of Science and Technology of China , Jinzhai Road 96 , 230026 Hefei , China
| | - Yujia Wang
- Shenyang National Laboratory for Materials Science , Institute of Metal Research, Chinese Academy of Sciences , Wenhua Road 72 , 110016 Shenyang , China
| | - Mengjiao Han
- Shenyang National Laboratory for Materials Science , Institute of Metal Research, Chinese Academy of Sciences , Wenhua Road 72 , 110016 Shenyang , China
- University of Chinese Academy of Sciences , Yuquan Road 19 , 100049 Beijing , China
| | - Jinyuan Ma
- Shenyang National Laboratory for Materials Science , Institute of Metal Research, Chinese Academy of Sciences , Wenhua Road 72 , 110016 Shenyang , China
- University of Science and Technology of China , Jinzhai Road 96 , 230026 Hefei , China
- State Key Lab of Advanced Processing and Recycling on Non-ferrous Metals , Lanzhou University of Technology , Langongping Road 287 , 730050 Lanzhou , China
| | - Bo Wu
- Shenyang National Laboratory for Materials Science , Institute of Metal Research, Chinese Academy of Sciences , Wenhua Road 72 , 110016 Shenyang , China
- University of Science and Technology of China , Jinzhai Road 96 , 230026 Hefei , China
| | - Wentao Hu
- Shenyang National Laboratory for Materials Science , Institute of Metal Research, Chinese Academy of Sciences , Wenhua Road 72 , 110016 Shenyang , China
- University of Science and Technology of China , Jinzhai Road 96 , 230026 Hefei , China
| | - Xiuliang Ma
- Shenyang National Laboratory for Materials Science , Institute of Metal Research, Chinese Academy of Sciences , Wenhua Road 72 , 110016 Shenyang , China
- State Key Lab of Advanced Processing and Recycling on Non-ferrous Metals , Lanzhou University of Technology , Langongping Road 287 , 730050 Lanzhou , China
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117
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Liu L, Rojac T, Damjanovic D, Di Michiel M, Daniels J. Frequency-dependent decoupling of domain-wall motion and lattice strain in bismuth ferrite. Nat Commun 2018; 9:4928. [PMID: 30467315 PMCID: PMC6250669 DOI: 10.1038/s41467-018-07363-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2018] [Accepted: 10/11/2018] [Indexed: 11/14/2022] Open
Abstract
Dynamics of domain walls are among the main features that control strain mechanisms in ferroic materials. Here, we demonstrate that the domain-wall-controlled piezoelectric behaviour in multiferroic BiFeO3 is distinct from that reported in classical ferroelectrics. In situ X-ray diffraction was used to separate the electric-field-induced lattice strain and strain due to displacements of non-180° domain walls in polycrystalline BiFeO3 over a wide frequency range. These piezoelectric strain mechanisms have opposing trends as a function of frequency. The lattice strain increases with increasing frequency, showing negative piezoelectric phase angle (i.e., strain leads the electric field), an unusual feature so far demonstrated only in the total macroscopic piezoelectric response. Domain-wall motion exhibits the opposite behaviour, it decreases in magnitude with increasing frequency, showing more common positive piezoelectric phase angle (i.e., strain lags behind the electric field). Charge redistribution at conducting domain walls, oriented differently in different grain families, is demonstrated to be the cause. Conductive domain walls of ferroelectric materials are considered for device applications demanding a fundamental understanding of their dynamics. Here, frequency-dependent decoupling of strains upon electric field cycling in BiFeO3 is demonstrated to arise from conductive domain walls.
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Affiliation(s)
- Lisha Liu
- School of Materials Science and Engineering, UNSW, 2052, Sydney, Australia
| | - Tadej Rojac
- Electronic Ceramics Department, Jozef Stefan Institute, 1000, Ljubljana, Slovenia
| | - Dragan Damjanovic
- Group for Ferroelectrics and Functional Oxides, Swiss Federal Institute of Technology in Lausanne-EPFL, 1015, Lausanne, Switzerland
| | | | - John Daniels
- School of Materials Science and Engineering, UNSW, 2052, Sydney, Australia.
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118
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Vila-Fungueiriño JM, Gómez A, Antoja-Lleonart J, Gázquez J, Magén C, Noheda B, Carretero-Genevrier A. Direct and converse piezoelectric responses at the nanoscale from epitaxial BiFeO 3 thin films grown by polymer assisted deposition. NANOSCALE 2018; 10:20155-20161. [PMID: 30259954 DOI: 10.1039/c8nr05737k] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
We use an original water-based chemical method to grow pure epitaxial BiFeO3 (BFO) ultra-thin films with excellent piezoelectric properties. Particularly, we show that this novel chemical route produces higher natural ferroelectric domain size distribution and coercive field compared to similar BFO films grown by physical methods. Moreover, we measured the d33 piezoelectric coefficient of 60 nm thick BFO films by a direct approach, using Direct Piezoelectric Force Microscopy (DPFM). As a result, first piezo-generated charge maps of a very thin BFO layer were obtained applying this novel technology. We also performed a comparative study of the d33 coefficients between standard PFM analysis and DPFM microscopy showing similar values i.e. 17 pm V-1 and 22 pC N-1, respectively. Finally, we proved that the directionality of the piezoelectric effect in BFO ferroelectric thin films is preserved at low thickness dimensions demonstrating the potential of chemical processes for the development of low cost functional ferroelectric and piezoelectric devices.
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Affiliation(s)
- José Manuel Vila-Fungueiriño
- Institut d'Électronique et des Systèmes (IES), UMR 5214, CNRS - Université de Montpellier, 860 rue Saint Priest, 34095 Montpellier, France.
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119
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Wu H, Zhao X, Guan C, Zhao LD, Wu J, Song D, Li C, Wang J, Loh KP, Venkatesan TV, Pennycook SJ. The Atomic Circus: Small Electron Beams Spotlight Advanced Materials Down to the Atomic Scale. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2018; 30:e1802402. [PMID: 30306651 DOI: 10.1002/adma.201802402] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/15/2018] [Revised: 08/06/2018] [Indexed: 06/08/2023]
Abstract
Defects in crystalline materials have a tremendous impact on their functional behavior. Controlling and tuning of these imperfections can lead to marked improvements in their physical, electrical, magnetic, and optical properties. Thanks to the development of aberration-corrected (scanning) transmission electron microscopy (STEM/TEM), direct visualization of defects at multiple length scales has now become possible, including those critically important defects at the atomic scale. Thorough understanding of the nature and dynamics of these defects is the key to unraveling the fundamental origins of structure-property relationships. Such insight can therefore allow the creation of new materials with desired properties through appropriate defect engineering. Herein, several examples of new insights obtained from representative functional materials are shown, including piezoelectrics/ferroelectrics, oxide interfaces, thermoelectrics, electrocatalysts, and 2D materials.
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Affiliation(s)
- Haijun Wu
- Department of Materials Science and Engineering, National University of Singapore (NUS), Singapore, 117574, Singapore
| | - Xiaoxu Zhao
- Department of Materials Science and Engineering, National University of Singapore (NUS), Singapore, 117574, Singapore
- NUS Graduate School for Integrative Sciences and Engineering, National University of Singapore, 13 Centre for Life Sciences, #05-01, 28 Medical Drive, Singapore, 117456, Singapore
| | - Cao Guan
- Department of Materials Science and Engineering, National University of Singapore (NUS), Singapore, 117574, Singapore
| | - Li-Dong Zhao
- School of Materials Science and Engineering, Beihang University, Beijing, 100191, China
| | - Jiagang Wu
- Department of Materials Science, Sichuan University, Chengdu, 610064, China
| | - Dongsheng Song
- NUSNNI-NanoCore, National University of Singapore, Singapore, 117411, Singapore
| | - Changjian Li
- Department of Materials Science and Engineering, National University of Singapore (NUS), Singapore, 117574, Singapore
| | - John Wang
- Department of Materials Science and Engineering, National University of Singapore (NUS), Singapore, 117574, Singapore
| | - Kian Ping Loh
- Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore, 117543, Singapore
- Centre for Advanced 2D Materials (CA2DM), National University of Singapore, 6 Science Drive 2, Singapore, 117546, Singapore
| | - Thirumalai V Venkatesan
- Department of Materials Science and Engineering, National University of Singapore (NUS), Singapore, 117574, Singapore
- NUSNNI-NanoCore, National University of Singapore, Singapore, 117411, Singapore
| | - Stephen J Pennycook
- Department of Materials Science and Engineering, National University of Singapore (NUS), Singapore, 117574, Singapore
- NUS Graduate School for Integrative Sciences and Engineering, National University of Singapore, 13 Centre for Life Sciences, #05-01, 28 Medical Drive, Singapore, 117456, Singapore
- Centre for Advanced 2D Materials (CA2DM), National University of Singapore, 6 Science Drive 2, Singapore, 117546, Singapore
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120
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Huang Z, Renshaw Wang X, Rusydi A, Chen J, Yang H, Venkatesan T. Interface Engineering and Emergent Phenomena in Oxide Heterostructures. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2018; 30:e1802439. [PMID: 30133012 DOI: 10.1002/adma.201802439] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/16/2018] [Revised: 07/06/2018] [Indexed: 06/08/2023]
Abstract
Complex oxide interfaces have mesmerized the scientific community in the last decade due to the possibility of creating tunable novel multifunctionalities, which are possible owing to the strong interaction among charge, spin, orbital, and structural degrees of freedom. Artificial interfacial modifications, which include defects, formal polarization, structural symmetry breaking, and interlayer interaction, have led to novel properties in various complex oxide heterostructures. These emergent phenomena not only serve as a platform for investigating strong electronic correlations in low-dimensional systems but also provide potentials for exploring next-generation electronic devices with high functionality. Herein, some recently developed strategies in engineering functional oxide interfaces and their emergent properties are reviewed.
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Affiliation(s)
- Zhen Huang
- NUSNNI-NanoCore, National University of Singapore, 5A Engineering Drive 1, Singapore, 117411, Singapore
| | - Xiao Renshaw Wang
- NUSNNI-NanoCore, National University of Singapore, 5A Engineering Drive 1, Singapore, 117411, Singapore
| | - Andrivo Rusydi
- NUSNNI-NanoCore, National University of Singapore, 5A Engineering Drive 1, Singapore, 117411, Singapore
| | - Jingsheng Chen
- NUSNNI-NanoCore, National University of Singapore, 5A Engineering Drive 1, Singapore, 117411, Singapore
| | - Hyunsoo Yang
- NUSNNI-NanoCore, National University of Singapore, 5A Engineering Drive 1, Singapore, 117411, Singapore
| | - Thirumalai Venkatesan
- NUSNNI-NanoCore, National University of Singapore, 5A Engineering Drive 1, Singapore, 117411, Singapore
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121
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Anomalously large lattice strain contributions from rhombohedral phases in BiFeO3-based high-temperature piezoceramics estimated by means of in-situ synchrotron x-ray diffraction. Ann Ital Chir 2018. [DOI: 10.1016/j.jeurceramsoc.2018.06.027] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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122
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Ferroelectric polymers exhibiting behaviour reminiscent of a morphotropic phase boundary. Nature 2018; 562:96-100. [DOI: 10.1038/s41586-018-0550-z] [Citation(s) in RCA: 126] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2018] [Accepted: 08/08/2018] [Indexed: 11/08/2022]
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123
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Ma J, Ma J, Zhang Q, Peng R, Wang J, Liu C, Wang M, Li N, Chen M, Cheng X, Gao P, Gu L, Chen LQ, Yu P, Zhang J, Nan CW. Controllable conductive readout in self-assembled, topologically confined ferroelectric domain walls. NATURE NANOTECHNOLOGY 2018; 13:947-952. [PMID: 30038370 DOI: 10.1038/s41565-018-0204-1] [Citation(s) in RCA: 51] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/13/2018] [Accepted: 06/18/2018] [Indexed: 05/12/2023]
Abstract
Charged domain walls in ferroelectrics exhibit a quasi-two-dimensional conduction path coupled to the surrounding polarization. They have been proposed for use as non-volatile memory with non-destructive operation and ultralow energy consumption. Yet the evolution of domain walls during polarization switching makes it challenging to control their location and conductance precisely, a prerequisite for controlled read-write schemes and for integration in scalable memory devices. Here, we explore and reversibly switch the polarization of square BiFeO3 nanoislands in a self-assembled array. Each island confines cross-shaped, charged domain walls in a centre-type domain. Electrostatic and geometric boundary conditions induce two stable domain configurations: centre-convergent and centre-divergent. We switch the polarization deterministically back and forth between these two states, which alters the domain wall conductance by three orders of magnitude, while the position of the domain wall remains static because of its confinement within the BiFeO3 islands.
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Affiliation(s)
- Ji Ma
- State Key Lab of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing, China
| | - Jing Ma
- State Key Lab of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing, China
| | - Qinghua Zhang
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Science, Beijing, China
| | - Renci Peng
- State Key Lab of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing, China
| | - Jing Wang
- State Key Lab of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing, China
- Department of Physics, Beijing Normal University, Beijing, China
| | - Chen Liu
- State Key Lab of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing, China
| | - Meng Wang
- State Key Laboratory of Low Dimensional Quantum Physics and Department of Physics, Tsinghua University, Beijing, China
| | - Ning Li
- International Center for Quantum Materials and Electron Microscopy Laboratory, School of Physics, Peking University, Beijing, China
| | - Mingfeng Chen
- State Key Lab of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing, China
| | - Xiaoxing Cheng
- Department of Materials Science and Engineering, Penn State University, University Park, PA, USA
| | - Peng Gao
- International Center for Quantum Materials and Electron Microscopy Laboratory, School of Physics, Peking University, Beijing, China
| | - Lin Gu
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Science, Beijing, China
| | - Long-Qing Chen
- State Key Lab of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing, China
- Department of Materials Science and Engineering, Penn State University, University Park, PA, USA
| | - Pu Yu
- State Key Laboratory of Low Dimensional Quantum Physics and Department of Physics, Tsinghua University, Beijing, China
| | - Jinxing Zhang
- Department of Physics, Beijing Normal University, Beijing, China.
| | - Ce-Wen Nan
- State Key Lab of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing, China.
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124
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Edwards D, Browne N, Holsgrove KM, Naden AB, Sayedaghaee SO, Xu B, Prosandeev S, Wang D, Mazumdar D, Duchamp M, Gupta A, Kalinin SV, Arredondo M, McQuaid RGP, Bellaiche L, Gregg JM, Kumar A. Giant resistive switching in mixed phase BiFeO 3via phase population control. NANOSCALE 2018; 10:17629-17637. [PMID: 30204201 DOI: 10.1039/c8nr03653e] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Highly-strained coherent interfaces, between rhombohedral-like (R) and tetragonal-like (T) phases in BiFeO3 thin films, often show enhanced electrical conductivity in comparison to non-interfacial regions. In principle, changing the population and distribution of these interfaces should therefore allow different resistance states to be created. However, doing this controllably has been challenging to date. Here, we show that local thin film phase microstructures (and hence R-T interface densities) can be changed in a thermodynamically predictable way (predictions made using atomistic simulations) by applying different combinations of mechanical stress and electric field. We use both pressure and electric field to reversibly generate metastable changes in microstructure that result in very large changes of resistance of up to 108%, comparable to those seen in Tunnelling Electro-Resistance (TER) devices.
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Affiliation(s)
- David Edwards
- School of Mathematics and Physics, Queen's University Belfast, Belfast, BT7 1NN, UK.
| | - Niall Browne
- School of Mathematics and Physics, Queen's University Belfast, Belfast, BT7 1NN, UK.
| | - Kristina M Holsgrove
- School of Mathematics and Physics, Queen's University Belfast, Belfast, BT7 1NN, UK.
| | - Aaron B Naden
- School of Mathematics and Physics, Queen's University Belfast, Belfast, BT7 1NN, UK.
| | - Sayed O Sayedaghaee
- Microelectronics-Photonics Program and Physics Department, University of Arkansas, Fayetteville, Arkansas 72701, USA
| | - Bin Xu
- Physics Department and Institute for Nanoscience and Engineering, University of Arkansas, Fayetteville, Arkansas 72701, USA
| | - Sergey Prosandeev
- Physics Department and Institute for Nanoscience and Engineering, University of Arkansas, Fayetteville, Arkansas 72701, USA
| | - Dawei Wang
- Electronic Materials Research Laboratory, Key Laboratory of the Ministry of Education and International Center for Dielectric Research, Xi'an Jiaotong University, Xi'an 710049, China
| | - Dipanjan Mazumdar
- Department of Physics, Southern Illinois University, Carbondale, Illinois 62901, USA
| | - Martial Duchamp
- Ernst Ruska Centre for Microscopy, Forschungszentrum Juelich, Juelich 52428, Germany and School of Materials Science and Engineering, Nanyang Technological University, Singapore 639798, Singapore
| | - Arunava Gupta
- Center for Materials for Information Technology, University of Alabama, Tuscaloosa, Alabama 35487, USA
| | - Sergei V Kalinin
- Center for Nanophase Material Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - Miryam Arredondo
- School of Mathematics and Physics, Queen's University Belfast, Belfast, BT7 1NN, UK.
| | - Raymond G P McQuaid
- School of Mathematics and Physics, Queen's University Belfast, Belfast, BT7 1NN, UK.
| | - Laurent Bellaiche
- Physics Department and Institute for Nanoscience and Engineering, University of Arkansas, Fayetteville, Arkansas 72701, USA
| | - J Marty Gregg
- School of Mathematics and Physics, Queen's University Belfast, Belfast, BT7 1NN, UK.
| | - Amit Kumar
- School of Mathematics and Physics, Queen's University Belfast, Belfast, BT7 1NN, UK.
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125
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Zhang L, Chen J, Fan L, Diéguez O, Cao J, Pan Z, Wang Y, Wang J, Kim M, Deng S, Wang J, Wang H, Deng J, Yu R, Scott JF, Xing X. Giant polarization in super-tetragonal thin films through interphase strain. SCIENCE (NEW YORK, N.Y.) 2018; 361:494-497. [PMID: 30072536 DOI: 10.1126/science.aan2433] [Citation(s) in RCA: 72] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Received: 03/17/2017] [Accepted: 05/31/2018] [Indexed: 11/02/2022]
Abstract
Strain engineering has emerged as a powerful tool to enhance the performance of known functional materials. Here we demonstrate a general and practical method to obtain super-tetragonality and giant polarization using interphase strain. We use this method to create an out-of-plane-to-in-plane lattice parameter ratio of 1.238 in epitaxial composite thin films of tetragonal lead titanate (PbTiO3), compared to 1.065 in bulk. These thin films with super-tetragonal structure possess a giant remanent polarization, 236.3 microcoulombs per square centimeter, which is almost twice the value of known ferroelectrics. The super-tetragonal phase is stable up to 725°C, compared to the bulk transition temperature of 490°C. The interphase-strain approach could enhance the physical properties of other functional materials.
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Affiliation(s)
- Linxing Zhang
- Department of Physical Chemistry, University of Science and Technology Beijing, Beijing 100083, China
| | - Jun Chen
- Department of Physical Chemistry, University of Science and Technology Beijing, Beijing 100083, China. .,State Key Laboratory for Advanced Metals and Materials, University of Science and Technology Beijing, Beijing 100083, China
| | - Longlong Fan
- Department of Physical Chemistry, University of Science and Technology Beijing, Beijing 100083, China
| | - Oswaldo Diéguez
- Department of Materials Science and Engineering, Faculty of Engineering, The Raymond and Beverly Sackler Center for Computational Molecular and Materials Science, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Jiangli Cao
- Institute of Advanced Materials and Technology, University of Science and Technology Beijing, Beijing 100083, China
| | - Zhao Pan
- Department of Physical Chemistry, University of Science and Technology Beijing, Beijing 100083, China
| | - Yilin Wang
- Department of Physical Chemistry, University of Science and Technology Beijing, Beijing 100083, China
| | - Jinguo Wang
- Department of Materials Science and Engineering, University of Texas at Dallas, Richardson, TX 75080, USA
| | - Moon Kim
- Department of Materials Science and Engineering, University of Texas at Dallas, Richardson, TX 75080, USA
| | - Shiqing Deng
- National Center for Electron Microscopy in Beijing, School of Materials Science and Engineering, The State Key Laboratory of New Ceramics and Fine Processing, Key Laboratory of Advanced Materials (MOE), Tsinghua University, Beijing 100084, China
| | - Jiaou Wang
- Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China
| | - Huanhua Wang
- Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China
| | - Jinxia Deng
- Department of Physical Chemistry, University of Science and Technology Beijing, Beijing 100083, China
| | - Ranbo Yu
- Department of Physical Chemistry, University of Science and Technology Beijing, Beijing 100083, China
| | - James F Scott
- School of Chemistry and School of Physics, St Andrews University, St Andrews, Fife KY16 9ST, Scotland
| | - Xianran Xing
- Department of Physical Chemistry, University of Science and Technology Beijing, Beijing 100083, China. .,State Key Laboratory for Advanced Metals and Materials, University of Science and Technology Beijing, Beijing 100083, China
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126
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Li L, Jokisaari JR, Zhang Y, Cheng X, Yan X, Heikes C, Lin Q, Gadre C, Schlom DG, Chen LQ, Pan X. Control of Domain Structures in Multiferroic Thin Films through Defect Engineering. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2018; 30:e1802737. [PMID: 30084144 DOI: 10.1002/adma.201802737] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2018] [Revised: 07/01/2018] [Indexed: 06/08/2023]
Abstract
Domain walls (DWs) have become an essential component in nanodevices based on ferroic thin films. The domain configuration and DW stability, however, are strongly dependent on the boundary conditions of thin films, which make it difficult to create complex ordered patterns of DWs. Here, it is shown that novel domain structures, that are otherwise unfavorable under the natural boundary conditions, can be realized by utilizing engineered nanosized structural defects as building blocks for reconfiguring DW patterns. It is directly observed that an array of charged defects, which are located within a monolayer thickness, can be intentionally introduced by slightly changing substrate temperature during the growth of multiferroic BiFeO3 thin films. These defects are strongly coupled to the domain structures in the pretemperature-change portion of the BiFeO3 film and can effectively change the configuration of newly grown domains due to the interaction between the polarization and the defects. Thus, two types of domain patterns are integrated into a single film without breaking the DW periodicity. The potential use of these defects for building complex patterns of conductive DWs is also demonstrated.
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Affiliation(s)
- Linze Li
- Department of Chemical Engineering and Materials Science, University of California, Irvine, CA, 92697, USA
| | - Jacob R Jokisaari
- Department of Materials Science and Engineering, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Yi Zhang
- Department of Chemical Engineering and Materials Science, University of California, Irvine, CA, 92697, USA
| | - Xiaoxing Cheng
- Department of Materials Science and Engineering, Penn State University, University Park, PA, 16802, USA
| | - Xingxu Yan
- Department of Chemical Engineering and Materials Science, University of California, Irvine, CA, 92697, USA
| | - Colin Heikes
- Department of Materials Science and Engineering, Cornell University, Ithaca, NY, 14853, USA
| | - Qiyin Lin
- Irvine Materials Research Institute, University of California, Irvine, CA, 92697, USA
| | - Chaitanya Gadre
- Department of Chemical Engineering and Materials Science, University of California, Irvine, CA, 92697, USA
| | - Darrell G Schlom
- Department of Materials Science and Engineering, Cornell University, Ithaca, NY, 14853, USA
- Kavli Institute at Cornell for Nanoscale Science, Ithaca, NY, 14853, USA
| | - Long-Qing Chen
- Department of Materials Science and Engineering, Penn State University, University Park, PA, 16802, USA
| | - Xiaoqing Pan
- Department of Chemical Engineering and Materials Science, University of California, Irvine, CA, 92697, USA
- Irvine Materials Research Institute, University of California, Irvine, CA, 92697, USA
- Department of Physics and Astronomy, University of California, Irvine, CA, 92697, USA
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127
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The effect of scanning jitter on geometric phase analysis in STEM images. Ultramicroscopy 2018; 194:167-174. [PMID: 30145381 DOI: 10.1016/j.ultramic.2018.07.011] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2018] [Revised: 06/21/2018] [Accepted: 07/28/2018] [Indexed: 11/22/2022]
Abstract
Geometric phase analysis (GPA) is a useful method to map strain distribution in atomically resolved scanning/transmission electron microscopy (S/TEM) images. Nevertheless, the inevitable periodic jitter of electron probe in STEM along the scanning direction due to the interference of electric power supply, including grounding, can give rise to major artifacts, as evidenced by the appearance of satellite spots surrounding all main peaks in the power spectrum of the images. Here we reveal the origin of the image artifacts related to the probe jitter by mapping the image distortion component εxx using the GPA algorithm. The effect is verified by introducing a periodic displacement field to a STEM image simulated from a perfect crystal structure, and the calculated εxx maps show very good agreement with the experimental observations. Based on the quantitative analysis of the images distortion, we propose and test a feasible strategy to eliminate the effect of probe jitter from STEM images. Successful examples illustrate that the approach can help improve the accuracy in quantification of STEM images.
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128
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Wang C, Chen C, Chang CH, Tsai HS, Pandey P, Xu C, Böttger R, Chen D, Zeng YJ, Gao X, Helm M, Zhou S. Defect-Induced Exchange Bias in a Single SrRuO 3 Layer. ACS APPLIED MATERIALS & INTERFACES 2018; 10:27472-27476. [PMID: 30033715 DOI: 10.1021/acsami.8b07918] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Exchange bias stems from the interaction between different magnetic phases, and therefore, it generally occurs in magnetic multilayers. Here, we present a large exchange bias in a single SrRuO3 layer induced by helium ion irradiation. When the fluence increases, the induced defects not only suppress the magnetization and the Curie temperature but also drive a metal-insulator transition at a low temperature. In particular, a large exchange bias field up to ∼0.36 T can be created by the irradiation. This large exchange bias is related to the coexistence of different magnetic and structural phases that are introduced by embedded defects. Our work demonstrates that spintronic properties in complex oxides can be created and enhanced by applying ion irradiation.
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Affiliation(s)
- Changan Wang
- Institute of Ion Beam Physics and Materials Research , Helmholtz-Zentrum Dresden-Rossendorf , Bautzner Landstr. 400 , 01328 Dresden , Germany
- Technische Universität Dresden , D-01062 Dresden , Germany
- Shenzhen Key Laboratory of Laser Engineering, College of Optoelectronic Engineering , Shenzhen University , 518060 Shenzhen , China
| | | | - Ching-Hao Chang
- Leibniz-Institute for Solid State and Materials Research , Helmholtzstrasse 20 , 01069 Dresden , Germany
| | - Hsu-Sheng Tsai
- Institute of Ion Beam Physics and Materials Research , Helmholtz-Zentrum Dresden-Rossendorf , Bautzner Landstr. 400 , 01328 Dresden , Germany
| | - Parul Pandey
- Institute of Ion Beam Physics and Materials Research , Helmholtz-Zentrum Dresden-Rossendorf , Bautzner Landstr. 400 , 01328 Dresden , Germany
| | - Chi Xu
- Institute of Ion Beam Physics and Materials Research , Helmholtz-Zentrum Dresden-Rossendorf , Bautzner Landstr. 400 , 01328 Dresden , Germany
| | - Roman Böttger
- Institute of Ion Beam Physics and Materials Research , Helmholtz-Zentrum Dresden-Rossendorf , Bautzner Landstr. 400 , 01328 Dresden , Germany
| | | | - Yu-Jia Zeng
- Shenzhen Key Laboratory of Laser Engineering, College of Optoelectronic Engineering , Shenzhen University , 518060 Shenzhen , China
| | | | - Manfred Helm
- Institute of Ion Beam Physics and Materials Research , Helmholtz-Zentrum Dresden-Rossendorf , Bautzner Landstr. 400 , 01328 Dresden , Germany
- Technische Universität Dresden , D-01062 Dresden , Germany
| | - Shengqiang Zhou
- Institute of Ion Beam Physics and Materials Research , Helmholtz-Zentrum Dresden-Rossendorf , Bautzner Landstr. 400 , 01328 Dresden , Germany
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129
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Yao J, Song X, Gao X, Tian G, Li P, Fan H, Huang Z, Yang W, Chen D, Fan Z, Zeng M, Liu JM. Electrically Driven Reversible Magnetic Rotation in Nanoscale Multiferroic Heterostructures. ACS NANO 2018; 12:6767-6776. [PMID: 29957931 DOI: 10.1021/acsnano.8b01936] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Electrically driven magnetic switching (EDMS) is highly demanded for next-generation advanced memories or spintronic devices. The key challenge is to achieve repeatable and reversible EDMS at sufficiently small scale. In this work, we reported an experimental realization of room-temperature, electrically driven, reversible, and robust 120° magnetic state rotation in nanoscale multiferroic heterostructures consisting of a triangular Co nanomagnet array on tetragonal BiFeO3 films, which can be directly monitored by magnetic force microscope (MFM) imaging. The observed reversible magnetic switching in an individual nanomagnet can be triggered by a small electric pulse within 10 V with an ultrashort time of ∼10 ns, which also demonstrates sufficient switching cycling and months-long retention lifetime. A mechanism based on synergic effects of interfacial strain and exchange coupling plus shape anisotropy was also proposed, which was also verified by micromagnetic simulations. Our results create an avenue to engineer the nanoscale EDMS for low-power-consumption, high-density, nonvolatile magnetoelectric memories and beyond.
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Affiliation(s)
- Junxiang Yao
- Institute for Advanced Materials and Guangdong Provincial Key Laboratory of Quantum Engineering and Quantum Materials, South China Academy of Advanced Optoelectronics , 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 Academy of Advanced Optoelectronics , South China Normal University , Guangzhou 510006 , China
| | - Xingsen Gao
- Institute for Advanced Materials and Guangdong Provincial Key Laboratory of Quantum Engineering and Quantum Materials, South China Academy of Advanced Optoelectronics , South China Normal University , Guangzhou 510006 , China
| | - Guo Tian
- Institute for Advanced Materials and Guangdong Provincial Key Laboratory of Quantum Engineering and Quantum Materials, South China Academy of Advanced Optoelectronics , 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 Academy of Advanced Optoelectronics , 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 Academy of Advanced Optoelectronics , South China Normal University , Guangzhou 510006 , China
| | - Zhifeng Huang
- Institute for Advanced Materials and Guangdong Provincial Key Laboratory of Quantum Engineering and Quantum Materials, South China Academy of Advanced Optoelectronics , South China Normal University , Guangzhou 510006 , China
| | - Wenda Yang
- Institute for Advanced Materials and Guangdong Provincial Key Laboratory of Quantum Engineering and Quantum Materials, South China Academy of Advanced Optoelectronics , 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 Academy of Advanced Optoelectronics , 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 Academy of Advanced Optoelectronics , 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 Academy of Advanced Optoelectronics , South China Normal University , Guangzhou 510006 , China
| | - Jun-Ming Liu
- Laboratory of Solid State Microstructures and Innovation Center of Advanced Microstructures , Nanjing University , Nanjing 21009 , China
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130
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Graf ME, Di Napoli S, Barral MA, Saleh Medina LM, Negri RM, Sepliarsky M, Llois AM. Rhombohedral R3c to orthorhombic Pnma phase transition induced by Y-doping in BiFeO 3. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2018; 30:285701. [PMID: 29790855 DOI: 10.1088/1361-648x/aac74f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
In this work we study, by means of ab initio calculations, the structural, electronic and magnetic properties of Y-doped BiFeO3 compounds. We determine that there is a morphotropic phase boundary at an yttrium concentration of [Formula: see text], where the structure changes from R3c to Pnma. This structural transition is driven by the chemical pressure induced by the dopant. By analyzing the evolution of the oxygen octahedral tilts we find an enhanced antiferrodistortive distortion when increasing the Y-doping, together with a reduction of the ferroelectric distorsion, that gives rise to a smaller value of the electric polarization. These cooperative effects should lead to a larger canting of the Fe magnetic moments and to a larger ferromagnetic response in the R3c phase, as it is observed in the experiments.
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Affiliation(s)
- M E Graf
- Instituto de Física Rosario (CONICET-UNR), Rosario, Argentina
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131
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Hojo H, Oka K, Shimizu K, Yamamoto H, Kawabe R, Azuma M. Development of Bismuth Ferrite as a Piezoelectric and Multiferroic Material by Cobalt Substitution. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2018; 30:e1705665. [PMID: 29920786 DOI: 10.1002/adma.201705665] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2017] [Revised: 03/06/2018] [Indexed: 06/08/2023]
Abstract
Bismuth ferrite (BiFeO3 ) is the most widely studied multiferroic material with robust ferroelectricity and antiferromagnetic ordering at room temperature. One of the possible device applications of this material is one that utilizes the ferroelectric/piezoelectric property itself such as ferroelectric memory components, actuators, and so on. Other applications are more challenging and make full use of its multiferroic property to realize novel spintronics and magnetic memory devices, which can be addressed electrically as well as magnetically. This progress report summarizes the recent attempt to control the piezoelectric and magnetic properties of BiFeO3 by cobalt substitution.
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Affiliation(s)
- Hajime Hojo
- Laboratory for Materials and Structures, Tokyo Institute of Technology, Yokohama, 226-8503, Japan
| | - Kengo Oka
- Department of Applied Chemistry, Faculty of Science and Engineering, Chuo University, Tokyo, 112-8551, Japan
| | - Keisuke Shimizu
- Laboratory for Materials and Structures, Tokyo Institute of Technology, Yokohama, 226-8503, Japan
| | - Hajime Yamamoto
- Laboratory for Materials and Structures, Tokyo Institute of Technology, Yokohama, 226-8503, Japan
| | - Ryo Kawabe
- Laboratory for Materials and Structures, Tokyo Institute of Technology, Yokohama, 226-8503, Japan
| | - Masaki Azuma
- Laboratory for Materials and Structures, Tokyo Institute of Technology, Yokohama, 226-8503, Japan
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132
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Magnetic Properties and Spontaneous Polarization of La-, Mn- and N-Doped Tetragonal BiFeO₃: A First-Principles Study. MATERIALS 2018; 11:ma11060985. [PMID: 29891798 PMCID: PMC6025010 DOI: 10.3390/ma11060985] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/18/2018] [Revised: 06/04/2018] [Accepted: 06/08/2018] [Indexed: 11/16/2022]
Abstract
Multiferroic materials have been receiving attention for their potential applications in multifunctional devices. Chemical substitution is an effective method for improving the physical properties of BiFeO3 (BFO). However, different experimental results have been reported for Lanthanum- (La-) and Manganese (Mn) -doped BFO ceramics. Here, we systematically studied the magnetic properties and spontaneous polarization of La-, Mn-, and Nitrogen (N) -doped tetragonal BiFeO3 using density functional theory with the generalized gradient approximation and U-value method. The calculated results demonstrated that the systems show ferromagnetism with Mn and N doping, whereas no magnetization was found with La doping in G- and C-type antiferromagnetic orderings. Our research further revealed that the ferromagnetism is attributed to the p-d orbital hybridization. Berry-phase polarization calculations predicted a large polarization of 149.2 µC/cm2 along the [001] direction of pure tetragonal BFO. We found that La and N substitution had little influence on the spontaneous polarization, whereas Mn substitution reduced the spontaneous polarization. The reduced energy barrier heights of the doped systems indicate the reduced stability of the off-centering ferroelectricity against the thermal agitation. These findings provide greater understanding for controlling and tuning the multiferroic properties of BFO.
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133
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Zhang Y, Jie W, Chen P, Liu W, Hao J. Ferroelectric and Piezoelectric Effects on the Optical Process in Advanced Materials and Devices. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2018; 30:e1707007. [PMID: 29888451 DOI: 10.1002/adma.201707007] [Citation(s) in RCA: 52] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2017] [Revised: 02/05/2018] [Indexed: 05/12/2023]
Abstract
Piezoelectric and ferroelectric materials have shown great potential for control of the optical process in emerging materials. There are three ways for them to impact on the optical process in various materials. They can act as external perturbations, such as ferroelectric gating and piezoelectric strain, to tune the optical properties of the materials and devices. Second, ferroelectricity and piezoelectricity as innate attributes may exist in some optoelectronic materials, which can couple with other functional features (e.g., semiconductor transport, photoexcitation, and photovoltaics) in the materials giving rise to unprecedented device characteristics. The last way is artificially introducing optical functionalities into ferroelectric and piezoelectric materials and devices, which provides an opportunity for investigating the intriguing interplay between the parameters (e.g., electric field, temperature, and strain) and the introduced optical properties. Here, the tuning strategies, fundamental mechanisms, and recent progress in ferroelectric and piezoelectric effects modulating the optical properties of a wide spectrum of materials, including lanthanide-doped phosphors, quantum dots, 2D materials, wurtzite-type semiconductors, and hybrid perovskites, are presented. Finally, the future outlook and challenges of this exciting field are suggested.
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Affiliation(s)
- Yang Zhang
- Institute of Modern Optics, Nankai University, Tianjin, 300071, China
| | - Wenjing Jie
- Department of Applied Physics, The Hong Kong Polytechnic University, Kowloon, Hong Kong, P. R. China
- College of Chemistry and Materials Science, Sichuan Normal University, Chengdu, 610068, China
| | - Ping Chen
- Institute of Modern Optics, Nankai University, Tianjin, 300071, China
| | - Weiwei Liu
- Institute of Modern Optics, Nankai University, Tianjin, 300071, China
| | - Jianhua Hao
- Department of Applied Physics, The Hong Kong Polytechnic University, Kowloon, Hong Kong, P. R. China
- The Hong Kong Polytechnic University Shenzhen Research Institute, Shenzhen, 518057, China
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134
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Chen S, Guan C, Ke S, Zeng X, Huang C, Hu S, Yen F, Huang H, Lu Y, Chen L. Modulation of Abnormal Poisson's Ratios and Electronic Properties in Mixed-Valence Perovskite Manganite Films. ACS APPLIED MATERIALS & INTERFACES 2018; 10:18029-18035. [PMID: 29745233 DOI: 10.1021/acsami.7b19580] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Epitaxy and misfit strain imposed by underlying substrates have been intensively used to tailor the microstructure and electronic properties of oxide films, but this approach is largely restricted by commercially limited substrates. In contrast to the conventional epitaxial misfit strains with a positive Poisson's constant, we show here a tunable Poisson's ratio with anomalous values from negative, zero, to positive. This permits effective control over the out-of-plane lattice parameters that strongly correlate the magnetic and transport properties in perovskite mixed-valence La1- xSr xMnO3 thin films. Our results provide an unconventional approach to better modulation and understanding of elastic-mediated microstructures and physical properties of oxide films by engineering the Poisson's ratios.
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Affiliation(s)
- Shanquan Chen
- Shenzhen Key Laboratory of Special Functional Materials, College of Materials Science and Engineering , Shenzhen University , Nanshan District, Shenzhen , 518060 Guangdong , China
| | - Changxin Guan
- Shenzhen Key Laboratory of Special Functional Materials, College of Materials Science and Engineering , Shenzhen University , Nanshan District, Shenzhen , 518060 Guangdong , China
- Department of Physics , Southern University of Science and Technology , Nanshan District, Shenzhen , 518055 Guangdong , China
- Department of Materials Science and Engineering , Hubei University , Wuchang District, 430062 Hubei , China
| | - Shanming Ke
- Shenzhen Key Laboratory of Special Functional Materials, College of Materials Science and Engineering , Shenzhen University , Nanshan District, Shenzhen , 518060 Guangdong , China
| | - Xierong Zeng
- Shenzhen Key Laboratory of Special Functional Materials, College of Materials Science and Engineering , Shenzhen University , Nanshan District, Shenzhen , 518060 Guangdong , China
| | - Chuanwei Huang
- Shenzhen Key Laboratory of Special Functional Materials, College of Materials Science and Engineering , Shenzhen University , Nanshan District, Shenzhen , 518060 Guangdong , China
- Department of Physics , Southern University of Science and Technology , Nanshan District, Shenzhen , 518055 Guangdong , China
| | - Sixia Hu
- Department of Physics , Southern University of Science and Technology , Nanshan District, Shenzhen , 518055 Guangdong , China
| | - Fei Yen
- Department of Physics , Southern University of Science and Technology , Nanshan District, Shenzhen , 518055 Guangdong , China
| | - Haoliang Huang
- National Synchrotron Radiation Laboratory , University of Science and Technology of China , Hefei 230026 , P. R. China
| | - Yalin Lu
- National Synchrotron Radiation Laboratory , University of Science and Technology of China , Hefei 230026 , P. R. China
| | - Lang Chen
- Department of Physics , Southern University of Science and Technology , Nanshan District, Shenzhen , 518055 Guangdong , China
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135
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Sharma P, Kang KR, Liu YY, Jang BK, Li JY, Yang CH, Seidel J. Optimizing the electromechanical response in morphotropic BiFeO 3. NANOTECHNOLOGY 2018; 29:205703. [PMID: 29480164 DOI: 10.1088/1361-6528/aab226] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Affiliation(s)
- P Sharma
- School of Materials Science and Engineering, UNSW Australia, Sydney NSW 2052, Australia
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136
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Dedon LR, Chen Z, Gao R, Qi Y, Arenholz E, Martin LW. Strain-Driven Nanoscale Phase Competition near the Antipolar-Nonpolar Phase Boundary in Bi 0.7La 0.3FeO 3 Thin Films. ACS APPLIED MATERIALS & INTERFACES 2018; 10:14914-14921. [PMID: 29637778 DOI: 10.1021/acsami.8b02597] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Complex-oxide materials tuned to be near phase boundaries via chemistry/composition, temperature, pressure, etc. are known to exhibit large susceptibilities. Here, we observe a strain-driven nanoscale phase competition in epitaxially constrained Bi0.7La0.3FeO3 thin films near the antipolar-nonpolar phase boundary and explore the evolution of the structural, dielectric, (anti)ferroelectric, and magnetic properties with strain. We find that compressive and tensile strains can stabilize an antipolar PbZrO3-like Pbam phase and a nonpolar Pnma orthorhombic phase, respectively. Heterostructures grown with little to no strain exhibit a self-assembled nanoscale mixture of the two orthorhombic phases, wherein the relative fraction of each phase can be modified with film thickness. Subsequent investigation of the dielectric and (anti)ferroelectric properties reveals an electric-field-driven phase transformation from the nonpolar phase to the antipolar phase. X-ray linear dichroism reveals that the antiferromagnetic-spin axes can be effectively modified by the strain-induced phase transition. This evolution of antiferromagnetic-spin axes can be leveraged in exchange coupling between the antiferromagnetic Bi0.7La0.3FeO3 and a ferromagnetic Co0.9Fe0.1 layer to tune the ferromagnetic easy axis of the Co0.9Fe0.1. These results demonstrate that besides chemical alloying, epitaxial strain is an alternative and effective way to modify subtle phase relations and tune physical properties in rare earth-alloyed BiFeO3. Furthermore, the observation of antiferroelectric-antiferromagnetic properties in the Pbam Bi0.7La0.3FeO3 phase could be of significant scientific interest and great potential in magnetoelectric devices because of its dual antiferroic nature.
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Affiliation(s)
- Liv R Dedon
- Department of Materials Science and Engineering , University of California, Berkeley , Berkeley , California 94720 , United States
| | - Zuhuang Chen
- Department of Materials Science and Engineering , University of California, Berkeley , Berkeley , California 94720 , United States
- School of Materials Science and Engineering , Harbin Institute of Technology , Shenzhen 518055 , P. R. China
| | - Ran Gao
- Department of Materials Science and Engineering , University of California, Berkeley , Berkeley , California 94720 , United States
| | - Yajun Qi
- Department of Materials Science and Engineering , University of California, Berkeley , Berkeley , California 94720 , United States
- Department of Materials Science and Engineering , Hubei University , Wuhan 430062 , P. R. China
| | - Elke Arenholz
- Advanced Light Source , Lawrence Berkeley National Laboratory , Berkeley , California 94720 , United States
| | - Lane W Martin
- Department of Materials Science and Engineering , University of California, Berkeley , Berkeley , California 94720 , United States
- Materials Sciences Division , Lawrence Berkeley National Laboratory , Berkeley , California 94720 , United States
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137
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Alsubaie A, Sharma P, Lee JH, Kim JY, Yang CH, Seidel J. Uniaxial Strain-Controlled Ferroelastic Domain Evolution in BiFeO 3. ACS APPLIED MATERIALS & INTERFACES 2018; 10:11768-11775. [PMID: 29557167 DOI: 10.1021/acsami.8b01711] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
We investigate the effect of variable uniaxial tensile strain on the evolution of 71° ferroelastic domains in (001)-oriented epitaxial BiFeO3 (BFO) thin films using piezoresponse force microscopy (PFM). For this purpose, a newly designed bending stage has been employed, which allows tensile bending as wells as in situ PFM characterization. In situ PFM imaging reveals polarization-strain correlations at the nanoscale. Specifically, ferroelastic domains with in-plane polarization along the direction of applied tensile strain expand, whereas the adjoining domains with orthogonal in-plane polarization contract. The switching is mediated by significant domain wall roughening and opposite displacement of the successive walls. Further, the domains with long-range order are more susceptible to an applied external mechanical stimulus compared to the domains, which exhibit short-range periodicity. In addition, the imprint state of film reverses direction under applied tensile strain. Finally, the strain-induced changes in the domain structure and wall motion are fully reversible and revert to their as-grown state upon release of the applied stress. The strain-induced non-180° polarization rotation constitutes a route to control connected functionalities, such as magnetism, via coupled in-plane rotation of the magnetic plane in multiferroic BFO thin films.
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Affiliation(s)
- Abdullah Alsubaie
- School of Materials Science and Engineering , UNSW Sydney , Sydney , NSW 2052 , Australia
- School of Physics , Taif University , Taif 26571 , Kingdom of Saudi Arabia
| | - Pankaj Sharma
- School of Materials Science and Engineering , UNSW Sydney , Sydney , NSW 2052 , Australia
| | - Jin Hong Lee
- Unité Mixte de Physique , CNRS, Thales, Université Paris Sud, Université Paris-Saclay , 91767 Palaiseau , France
| | | | | | - Jan Seidel
- School of Materials Science and Engineering , UNSW Sydney , Sydney , NSW 2052 , Australia
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138
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Probing Ferroic States in Oxide Thin Films Using Optical Second Harmonic Generation. APPLIED SCIENCES-BASEL 2018. [DOI: 10.3390/app8040570] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Forthcoming low-energy consumption oxide electronics rely on the deterministic control of ferroelectric and multiferroic domain states at the nanoscale. In this review, we address the recent progress in the field of investigation of ferroic order in thin films and heterostructures, with a focus on non-invasive optical second harmonic generation (SHG). For more than 50 years, SHG has served as an established technique for probing ferroic order in bulk materials. Here, we will survey the specific new aspects introduced to SHG investigation of ferroelectrics and multiferroics by working with thin film structures. We show how SHG can probe complex ferroic domain patterns non-invasively and even if the lateral domain size is below the optical resolution limit or buried beneath an otherwise impenetrable cap layer. We emphasize the potential of SHG to distinguish contributions from individual (multi-) ferroic films or interfaces buried in a device or multilayer architecture. Special attention is given to monitoring switching events in buried ferroic domain- and domain-wall distributions by SHG, thus opening new avenues towards the determination of the domain dynamics. Another aspect studied by SHG is the role of strain. We will finally show that by integrating SHG into the ongoing thin film deposition process, we can monitor the emergence of ferroic order and properties in situ, while they emerge during growth. Our review closes with an outlook, emphasizing the present underrepresentation of ferroic switching dynamics in the study of ferroic oxide heterostructures.
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139
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Li L, Cheng X, Jokisaari JR, Gao P, Britson J, Adamo C, Heikes C, Schlom DG, Chen LQ, Pan X. Defect-Induced Hedgehog Polarization States in Multiferroics. PHYSICAL REVIEW LETTERS 2018; 120:137602. [PMID: 29694202 DOI: 10.1103/physrevlett.120.137602] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2017] [Indexed: 06/08/2023]
Abstract
Continuous developments in nanotechnology require new approaches to materials synthesis that can produce novel functional structures. Here, we show that nanoscale defects, such as nonstoichiometric nanoregions (NSNRs), can act as nano-building blocks for creating complex electrical polarization structures in the prototypical multiferroic BiFeO_{3}. An array of charged NSNRs are produced in BiFeO_{3} thin films by tuning the substrate temperature during film growth. Atomic-scale scanning transmission electron microscopy imaging reveals exotic polarization rotation patterns around these NSNRs. These polarization patterns resemble hedgehog or vortex topologies and can cause local changes in lattice symmetries leading to mixed-phase structures resembling the morphotropic phase boundary with high piezoelectricity. Phase-field simulations indicate that the observed polarization configurations are mainly induced by charged states at the NSNRs. Engineering defects thus may provide a new route for developing ferroelectric- or multiferroic-based nanodevices.
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Affiliation(s)
- Linze Li
- Department of Chemical Engineering and Materials Science, University of California-Irvine, Irvine, California 92697, USA
- Department of Materials Science and Engineering, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - Xiaoxing Cheng
- Department of Materials Science and Engineering, Penn State University, University Park, Pennsylvania 16802, USA
| | - Jacob R Jokisaari
- Department of Materials Science and Engineering, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - Peng Gao
- Department of Materials Science and Engineering, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - Jason Britson
- Department of Materials Science and Engineering, Penn State University, University Park, Pennsylvania 16802, USA
| | - Carolina Adamo
- Department of Materials Science and Engineering, Cornell University, Ithaca, New York 14853, USA
| | - Colin Heikes
- Department of Materials Science and Engineering, Cornell University, Ithaca, New York 14853, USA
| | - Darrell G Schlom
- Department of Materials Science and Engineering, Cornell University, Ithaca, New York 14853, USA
- Kavli Institute at Cornell for Nanoscale Science, Ithaca, New York 14853, USA
| | - Long-Qing Chen
- Department of Materials Science and Engineering, Penn State University, University Park, Pennsylvania 16802, USA
| | - Xiaoqing Pan
- Department of Chemical Engineering and Materials Science, University of California-Irvine, Irvine, California 92697, USA
- Department of Physics and Astronomy, University of California-Irvine, Irvine, California 92697, USA
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140
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Abstract
Large piezoelectric coefficients in polycrystalline lead zirconate titanate (PZT) are traditionally achieved through compositional design using a combination of chemical substitution with a donor dopant and adjustment of the zirconium to titanium compositional ratio to meet the morphotropic phase boundary (MPB). In this work, a different route to large piezoelectricity is demonstrated. Results reveal unexpectedly high piezoelectric coefficients at elevated temperatures and compositions far from the MPB. At temperatures near the Curie point, doping with 2 at% Sm results in exceptionally large piezoelectric coefficients of up to 915 pm/V. This value is approximately twice those of other donor dopants (e.g., 477 pm/V for Nb and 435 pm/V for La). Structural changes during the phase transitions of Sm-doped PZT show a pseudo-cubic phase forming ≈50 °C below the Curie temperature. Possible origins of these effects are discussed and the high piezoelectricity is posited to be due to extrinsic effects. The enhancement of the mechanism at elevated temperatures is attributed to the coexistence of tetragonal and pseudo-cubic phases, which enables strain accommodation during electromechanical deformation and interphase boundary motion. This work provides insight into possible routes for designing high performance piezoelectrics which are alternatives to traditional methods relying on MPB compositions.
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141
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Goswami S, Bhattacharya D, Ghosh CK, Ghosh B, Kaushik SD, Siruguri V, Krishna PSR. Nonmonotonic particle-size-dependence of magnetoelectric coupling in strained nanosized particles of BiFeO 3. Sci Rep 2018; 8:3728. [PMID: 29487340 PMCID: PMC5829220 DOI: 10.1038/s41598-018-21803-1] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2017] [Accepted: 02/12/2018] [Indexed: 11/28/2022] Open
Abstract
Using high resolution powder x-ray and neutron diffraction experiments, we determined the off-centered displacement of the ions within a unit cell and magnetoelectric coupling in nanoscale BiFeO3 (≈20–200 nm). We found that both the off-centered displacement of the ions and magnetoelectric coupling exhibit nonmonotonic variation with particle size. They increase as the particle size reduces from bulk and reach maximum around 30 nm. With further decrease in particle size, they decrease precipitously. The magnetoelectric coupling is determined by the anomaly in off-centering of ions around the magnetic transition temperature (TN). The ions, in fact, exhibit large anomalous displacement around the TN which is analyzed using group theoretical approach. It underlies the nonmonotonic particle-size-dependence of off-centre displacement of ions and magnetoelectric coupling. The nonmonotonic variation of magnetoelectric coupling with particle size is further verified by direct electrical measurement of remanent ferroelectric hysteresis loops at room temperature under zero and ∼20 kOe magnetic field. Competition between enhanced lattice strain and compressive pressure appears to be causing the nonmonotonic particle-size-dependence of off-centre displacement while coupling between piezo and magnetostriction leads to nonmonotonicity in the variation of magnetoelectric coupling.
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Affiliation(s)
- Sudipta Goswami
- Department of Solid State Physics, Indian Association for the Cultivation of Science, Kolkata, 700032, India.
| | - Dipten Bhattacharya
- Nanostructured Materials Division, CSIR-Central Glass and Ceramic Research Institute, Kolkata, 700032, India.
| | - Chandan K Ghosh
- School of Materials Science and Nanotechnology, Jadavpur University, Kolkata, 700032, India
| | - Barnali Ghosh
- Department of Materials Science, S. N. Bose National Center for Basic Sciences, Kolkata, 700098, India
| | - S D Kaushik
- UGC-DAE Consortium for Scientific Research, Bhabha Atomic Research Centre, Mumbai, 400085, India
| | - V Siruguri
- UGC-DAE Consortium for Scientific Research, Bhabha Atomic Research Centre, Mumbai, 400085, India
| | - P S R Krishna
- Solid State Physics Division, Bhabha Atomic Research Centre, Mumbai, 400085, India
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142
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Zhang L, Yuan Y, Lapano J, Brahlek M, Lei S, Kabius B, Gopalan V, Engel-Herbert R. Continuously Tuning Epitaxial Strains by Thermal Mismatch. ACS NANO 2018; 12:1306-1312. [PMID: 29320634 DOI: 10.1021/acsnano.7b07539] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Strain engineering of thin films is a conventionally employed approach to enhance material properties and to energetically prefer ground states that would otherwise not be attainable. Controlling strain states in perovskite oxide thin films is usually accomplished through coherent epitaxy by using lattice-mismatched substrates with similar crystal structures. However, the limited choice of suitable oxide substrates makes certain strain states experimentally inaccessible and a continuous tuning impossible. Here, we report a strategy to continuously tune epitaxial strains in perovskite films grown on Si(001) by utilizing the large difference of thermal expansion coefficients between the film and the substrate. By establishing an adsorption-controlled growth window for SrTiO3 thin films on Si using hybrid molecular beam epitaxy, the magnitude of strain can be solely attributed to thermal expansion mismatch, which only depends on the difference between growth and room temperature. Second-harmonic generation measurements revealed that structure properties of SrTiO3 films could be tuned by this method using films with different strain states. Our work provides a strategy to generate continuous strain states in oxide/semiconductor pseudomorphic buffer structures that could help achieve desired material functionalities.
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Affiliation(s)
- Lei Zhang
- Department of Materials Science and Engineering, ‡Materials Research Institute, §Department of Physics, and ∥Department of Chemistry, The Pennsylvania State University , University Park, Pennsylvania 16802, United States
| | - Yakun Yuan
- Department of Materials Science and Engineering, ‡Materials Research Institute, §Department of Physics, and ∥Department of Chemistry, The Pennsylvania State University , University Park, Pennsylvania 16802, United States
| | - Jason Lapano
- Department of Materials Science and Engineering, ‡Materials Research Institute, §Department of Physics, and ∥Department of Chemistry, The Pennsylvania State University , University Park, Pennsylvania 16802, United States
| | - Matthew Brahlek
- Department of Materials Science and Engineering, ‡Materials Research Institute, §Department of Physics, and ∥Department of Chemistry, The Pennsylvania State University , University Park, Pennsylvania 16802, United States
| | - Shiming Lei
- Department of Materials Science and Engineering, ‡Materials Research Institute, §Department of Physics, and ∥Department of Chemistry, The Pennsylvania State University , University Park, Pennsylvania 16802, United States
| | - Bernd Kabius
- Department of Materials Science and Engineering, ‡Materials Research Institute, §Department of Physics, and ∥Department of Chemistry, The Pennsylvania State University , University Park, Pennsylvania 16802, United States
| | - Venkatraman Gopalan
- Department of Materials Science and Engineering, ‡Materials Research Institute, §Department of Physics, and ∥Department of Chemistry, The Pennsylvania State University , University Park, Pennsylvania 16802, United States
| | - Roman Engel-Herbert
- Department of Materials Science and Engineering, ‡Materials Research Institute, §Department of Physics, and ∥Department of Chemistry, The Pennsylvania State University , University Park, Pennsylvania 16802, United States
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143
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Yang Y, Paillard C, Xu B, Bellaiche L. Photostriction and elasto-optic response in multiferroics and ferroelectrics from first principles. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2018; 30:073001. [PMID: 29300181 DOI: 10.1088/1361-648x/aaa51f] [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 present work reviews a series of recent first-principles studies devoted to the description of the interaction of light and strain in ferroelectric and multiferroic materials. Specifically, the modelling schemes used in these works to describe the so-called photostriction and elasto-optic effects are presented, in addition to the results and analysis provided by these ab initio calculations. In particular, the large importance of the piezoelectric effect in the polar direction in the photostriction of ferroelectric materials is stressed. Similarly, the occurrence of low-symmetry phases in lead titanate thin films under tensile strain is demonstrated to result in large elasto-optic constants. In addition, first-principle calculations allow to gain microscopic knowledge of subtle effects, for instance in the case of photostriction, where the deformation potential effect in directions perpendicular to the polar axis is shown to be almost as significant as the piezoelectric effect. As a result, the numerical methods presented here could propel the design of efficient opto-mechanical devices.
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Affiliation(s)
- Yurong Yang
- Department of Physics and Institute for Nanoscience and Engineering, University of Arkansas, Fayetteville, AR 72701, United States of America
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144
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Zhang Z, You L, Du J, Wang J, Jin Z, Ma G, Leng Y. Ultrafast electron-phonon coupling and photo-induced strain in the morphotropic phase boundary of Bi xDy 1-xFeO 3 films. Sci Rep 2018; 8:3258. [PMID: 29459659 PMCID: PMC5818539 DOI: 10.1038/s41598-018-21655-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2017] [Accepted: 02/08/2018] [Indexed: 11/29/2022] Open
Abstract
The interplay among ferroelectric, magnetic and elastic degrees of freedom in multiferroics is the key issues in condensed matters, which has been widely investigated by various methods. Here, using ultrafast two-color pump-probe spectroscopy, the picosecond electron-phonon and spin-lattice coupling process in Dysprosium doped-BiFeO3 (BDFO) films on SrTiO3 (STO) substrate have been investigated systematically. The Dy-doping induced structural transition and magnetic enhancement in BDFO is observed by ultrafast electron-phonon and spin-lattice interaction, respectively. The elastic anomalies in BDFO films are revealed by the photo-induced coherent acoustic phonon. With increasing the Dy doping ratio, the frequencies of the acoustic phonon in the films are modulated, and the phonon transmission coefficient between films and substrate is found to approach unity gradually. The ultrafast observation of the tunability of the ferroelectric, magnetic and the elastic properties in the morphotropic phase boundary of rare-earth doped BFO films provides new insights into the integration of BFO in next-generation high frequency electro-magnetic and electroacoustic devices.
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Affiliation(s)
- Zeyu Zhang
- State Key Laboratory of High Field Laser Physics, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai, 201800, China.,Department of Physics, Shanghai University, Shanghai, 200444, China
| | - Lu You
- School of Materials Science and Engineering, Nanyang Technological University, Singapore, 639798, Singapore
| | - Juan Du
- State Key Laboratory of High Field Laser Physics, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai, 201800, China.
| | - Junling Wang
- School of Materials Science and Engineering, Nanyang Technological University, Singapore, 639798, Singapore
| | - Zuanming Jin
- Department of Physics, Shanghai University, Shanghai, 200444, China
| | - Guohong Ma
- Department of Physics, Shanghai University, Shanghai, 200444, China.
| | - Yuxin Leng
- State Key Laboratory of High Field Laser Physics, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai, 201800, China.
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145
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Yang X, Zeng R, Ren Z, Wu Y, Chen X, Li M, Chen J, Zhao R, Zhou D, Liao Z, Tian H, Lu Y, Li X, Li J, Han G. Single-Crystal BiFeO 3 Nanoplates with Robust Antiferromagnetism. ACS APPLIED MATERIALS & INTERFACES 2018; 10:5785-5792. [PMID: 29368504 DOI: 10.1021/acsami.7b17449] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Freestanding and single-crystal BiFeO3 (BFO) nanoplates have been successfully synthesized by a fluoride ion-assisted hydrothermal method, and the thickness of the nanoplates can be effectively tailored from 80 to 380 nm by the concentration of fluoride ions. It is revealed that BFO nanoplates grew via an oriented attachment of layer by layer, giving rise to the formation of the inner interface within the nanoplates. In particular, antiferromagnetic (AFM) phase-transition temperature (Néel temperature, TN) of the BFO nanoplates is significantly enhanced from typical 370 to ∼512 °C, whereas the Curie temperature (TC) of the BFO nanoplates is determined to be ∼830 °C, in good agreement with a bulk value. The combination of scanning transmission electron microscopy, electron energy loss spectroscopy, and the first-principle calculations reveals that the interfacial tensile strain remarkably improves the stability of AFM ordering, accounting for the significant enhancement in TN of BFO plates. Correspondingly, the tensile strain induced the polarization and oxygen octahedral tilting has been observed near the interface. The findings presented here suggest that single-crystal BFO nanoplate is an ideal system for exploring an intrinsic magnetoelectric property, where a tensile strain can be a very promising approach to tailor AFM ordering and polarization rotation for an enhanced coupling effect.
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Affiliation(s)
- Xin Yang
- State Key Laboratory of Silicon Materials, School of Materials Science and Engineering, Cyrus Tang Center for Sensor Materials and Application, Zhejiang University , Hangzhou 310027, China
- Key Laboratory of Advanced Technique & Preparation for Renewable Energy Materials, Ministry of Education, Yunnan Normal University , Kunming 650500, China
| | - RongGuang Zeng
- Science and Technology on Surface Physics and Chemistry Laboratory , P.O. Box 718-35, Mianyang 621907, China
| | - ZhaoHui Ren
- State Key Laboratory of Silicon Materials, School of Materials Science and Engineering, Cyrus Tang Center for Sensor Materials and Application, Zhejiang University , Hangzhou 310027, China
| | - YanFei Wu
- Institute for Quantum Science and Engineering and Department of Physics, South University of Science and Technology of China , Shenzhen 518055, China
| | - Xing Chen
- Center of Electron Microscope, School of Materials Science and Engineering, Zhejiang University , Hangzhou 310027, China
| | - Ming Li
- State Key Laboratory of Silicon Materials, School of Materials Science and Engineering, Cyrus Tang Center for Sensor Materials and Application, Zhejiang University , Hangzhou 310027, China
| | - JiaLu Chen
- State Key Laboratory of Silicon Materials, School of Materials Science and Engineering, Cyrus Tang Center for Sensor Materials and Application, Zhejiang University , Hangzhou 310027, China
| | - RuoYu Zhao
- State Key Laboratory of Silicon Materials, School of Materials Science and Engineering, Cyrus Tang Center for Sensor Materials and Application, Zhejiang University , Hangzhou 310027, China
| | - DiKui Zhou
- State Key Laboratory of Silicon Materials, School of Materials Science and Engineering, Cyrus Tang Center for Sensor Materials and Application, Zhejiang University , Hangzhou 310027, China
| | - ZhiMin Liao
- State Key Laboratory for Mesoscopic Physics, School of Physics, Peking University , Beijing 100871, China
| | - He Tian
- Center of Electron Microscope, School of Materials Science and Engineering, Zhejiang University , Hangzhou 310027, China
| | - YunHao Lu
- State Key Laboratory of Silicon Materials, School of Materials Science and Engineering, Cyrus Tang Center for Sensor Materials and Application, Zhejiang University , Hangzhou 310027, China
| | - Xiang Li
- State Key Laboratory of Silicon Materials, School of Materials Science and Engineering, Cyrus Tang Center for Sensor Materials and Application, Zhejiang University , Hangzhou 310027, China
| | - JiXue Li
- Center of Electron Microscope, School of Materials Science and Engineering, Zhejiang University , Hangzhou 310027, China
| | - GaoRong Han
- State Key Laboratory of Silicon Materials, School of Materials Science and Engineering, Cyrus Tang Center for Sensor Materials and Application, Zhejiang University , Hangzhou 310027, China
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146
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Yao L, Inkinen S, Pacherova O, Jelinek M, van Dijken S, Tyunina M. Chemical-bond effect on epitaxial strain in perovskite sodium niobate. Phys Chem Chem Phys 2018; 20:4263-4268. [PMID: 29364292 DOI: 10.1039/c7cp08449h] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Epitaxial films and heterostructures of perovskite oxides attract tremendous scientific interest because of the unique phenomena therein. Especially important is the epitaxial growth of films subjected to substrate-induced misfit strain. We show here that in contrast to conventional misfit-controlled epitaxy, chemical bonds determine the crystal stability and strain in epitaxial films of sodium niobate on different cubic substrates. Strain relaxation in sodium niobate is independent of misfit magnitude and proceeds through perovskite-specific tilting of oxygen octahedra in addition to common defect formation. The observed structural relaxation evidences a major role of a large internal strain that originates from chemical bonds in the perovskite cell. The effect of chemical bonds on film strain is anticipated to also control the epitaxy of other perovskite oxides and related compounds.
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Affiliation(s)
- L Yao
- NanoSpin, Department of Applied Physics, Aalto University School of Science, P. O. Box 15100, FI-00076 Aalto, Finland
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147
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Wu SQ, Cheng S, Lu L, Liu M, Jin XW, Cheng SD, Mi SB. B-site ordering and strain-induced phase transition in double-perovskite La 2NiMnO 6 films. Sci Rep 2018; 8:2516. [PMID: 29410424 PMCID: PMC5802844 DOI: 10.1038/s41598-018-20812-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2017] [Accepted: 01/24/2018] [Indexed: 12/05/2022] Open
Abstract
The magnetic and electrical properties of complex oxide thin films are closely related to the phase stability and cation ordering, which demands that we understand the process-structure-property relationships microscopically in functional materials research. Here we study multiferroic thin films of double-perovskite La2NiMnO6 epitaxially grown on SrTiO3, KTaO3, LaAlO3 and DyScO3 substrates by pulsed laser deposition. The effect of epitaxial strains imposed by the substrate on the microstructural properties of La2NiMnO6 has been systematically investigated by means of advanced electron microscopy. It is found that La2NiMnO6 films under tensile strain exhibit a monoclinic structure, while under compressive strain the crystal structure of La2NiMnO6 films is rhombohedral. In addition, by optimizing the film deposition conditions a long-range ordering of B-site cations in La2NiMnO6 films has been obtained in both monoclinic and rhombohedral phases. Our results not only provide a strategy for tailoring phase stability by strain engineering, but also shed light on tuning B-site ordering by controlling film growth temperature in double-perovskite La2NiMnO6 films.
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Affiliation(s)
- Sheng-Qiang Wu
- State Key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong University, Xi'an, 710049, China
| | - Sheng Cheng
- School of Microelectronics, Xi'an Jiaotong University, Xi'an, 710049, China
| | - Lu Lu
- School of Microelectronics, Xi'an Jiaotong University, Xi'an, 710049, China
| | - Ming Liu
- School of Microelectronics, Xi'an Jiaotong University, Xi'an, 710049, China
| | - Xiao-Wei Jin
- School of Microelectronics, Xi'an Jiaotong University, Xi'an, 710049, China
| | - Shao-Dong Cheng
- State Key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong University, Xi'an, 710049, China.,School of Microelectronics, Xi'an Jiaotong University, Xi'an, 710049, China
| | - Shao-Bo Mi
- State Key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong University, Xi'an, 710049, China.
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148
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Liu H, Chen J, Huang H, Fan L, Ren Y, Pan Z, Deng J, Chen LQ, Xing X. Role of Reversible Phase Transformation for Strong Piezoelectric Performance at the Morphotropic Phase Boundary. PHYSICAL REVIEW LETTERS 2018; 120:055501. [PMID: 29481186 DOI: 10.1103/physrevlett.120.055501] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2017] [Indexed: 06/08/2023]
Abstract
A functional material with coexisting energetically equivalent phases often exhibits extraordinary properties such as piezoelectricity, ferromagnetism, and ferroelasticity, which is simultaneously accompanied by field-driven reversible phase transformation. The study on the interplay between such phase transformation and the performance is of great importance. Here, we have experimentally revealed the important role of field-driven reversible phase transformation in achieving enhanced electromechanical properties using in situ high-energy synchrotron x-ray diffraction combined with 2D geometry scattering technology, which can establish a comprehensive picture of piezoelectric-related microstructural evolution. High-throughput experiments on various Pb/Bi-based perovskite piezoelectric systems suggest that reversible phase transformation can be triggered by an electric field at the morphotropic phase boundary and the piezoelectric performance is highly related to the tendency of electric-field-driven phase transformation. A strong tendency of phase transformation driven by an electric field generates peak piezoelectric response. Further, phase-field modeling reveals that the polarization alignment and the piezoelectric response can be much enhanced by the electric-field-driven phase transformation. The proposed mechanism will be helpful to design and optimize the new piezoelectrics, ferromagnetics, or other related functional materials.
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Affiliation(s)
- Hui Liu
- Department of Physical Chemistry, University of Science and Technology Beijing, Beijing 100083, China
| | - Jun Chen
- Department of Physical Chemistry, University of Science and Technology Beijing, Beijing 100083, China
| | - Houbing Huang
- Department of Physics, University of Science and Technology Beijing, Beijing 100083, China
| | - Longlong Fan
- Department of Physical Chemistry, University of Science and Technology Beijing, Beijing 100083, China
| | - Yang Ren
- X-Ray Science Division, Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - Zhao Pan
- Department of Physical Chemistry, University of Science and Technology Beijing, Beijing 100083, China
| | - Jinxia Deng
- Department of Physical Chemistry, University of Science and Technology Beijing, Beijing 100083, China
| | - Long-Qing Chen
- Department of Materials Science and Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802, USA
| | - Xianran Xing
- Department of Physical Chemistry, University of Science and Technology Beijing, Beijing 100083, China
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149
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Nanopillars with E-field accessible multi-state (N ≥ 4) magnetization having giant magnetization changes in self-assembled BiFeO 3-CoFe 2O 4/Pb(Mg 1/3Nb 2/3)-38at%PbTiO 3 heterostructures. Sci Rep 2018; 8:1628. [PMID: 29374177 PMCID: PMC5786110 DOI: 10.1038/s41598-018-19673-8] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2017] [Accepted: 01/05/2018] [Indexed: 12/04/2022] Open
Abstract
We have deposited self-assembled BiFeO3-CoFe2O4 (BFO-CFO) thin films on (100)-oriented SrRuO3-buffered Pb(Mg1/3Nb2/3)0.62Ti0.38O3 (PMN-38PT) single crystal substrates. These heterostructures were used for the study of real-time changes in the magnetization with applied DC electric field (EDC). With increasing EDC, a giant magnetization change was observed along the out-of-plane (easy) axis. The induced magnetization changes of the CFO nanopillars in the BFO/CFO layer were about ΔM/MrDC = 93% at EDC = −3 kv/cm. A giant converse magnetoelectric (CME) coefficient of 1.3 × 10−7 s/m was estimated from the data. By changing EDC, we found multiple(N ≥ 4) unique possible values of a stable magnetization with memory on the removal of the field.
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150
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Bae IT, Ichinose T, Han MG, Zhu Y, Yasui S, Naganuma H. Tensile stress effect on epitaxial BiFeO 3 thin film grown on KTaO 3. Sci Rep 2018; 8:893. [PMID: 29343784 PMCID: PMC5772049 DOI: 10.1038/s41598-018-19487-8] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2017] [Accepted: 01/02/2018] [Indexed: 11/19/2022] Open
Abstract
Comprehensive crystal structural study is performed for BiFeO3 (BFO) film grown on KTaO3 (KTO) substrate using transmission electron microscopy (TEM) and x-ray diffraction (XRD). Nano-beam electron diffraction (NBED) combined with structure factor calculation and high resolution TEM images clearly reveal that the crystal structure within BFO thin film is rhombohedral BFO, i.e., bulk BFO phase. Epitaxial relationship found by NBED indicates the BFO film grows in a manner that minimizes lattice mismatch with KTO. It further suggests BFO film is under slight biaxial tensile stress (~0.35%) along in-plane direction. XRD reveals BFO lattice is under compressive stress (~1.6%), along out-of-plane direction as a result of the biaxial tensile strain applied along in-plane direction. This leads to Poisson’s ratio of ~0.68. In addition, we demonstrate (1) why hexagonal notation rather than pseudocubic one is required for accurate BFO phase evaluation and (2) a new XRD method that shows how rhombohedral BFO can readily be identified among other phases by measuring a rhombohedral specific Bragg’s reflection.
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Affiliation(s)
- In-Tae Bae
- Small Scale Systems Integration and Packaging Center, State University of New York at Binghamton, Binghamton, New York, 13902, USA.
| | - Tomohiro Ichinose
- Department of Applied Physics, Graduate School of Engineering, Tohoku University, Sendai, 980-8579, Japan
| | - Myung-Geun Han
- Condensed Matter Physics and Materials Science, Brookhaven National Laboratory, Upton, NY, 11973, USA
| | - Yimei Zhu
- Condensed Matter Physics and Materials Science, Brookhaven National Laboratory, Upton, NY, 11973, USA
| | - Shintaro Yasui
- Laboratory for Materials and Structures, Tokyo Institute of Technology, 4259-J2-19, Nagatsuda-cho, Midori-ku, Yokohama, 226-8502, Japan
| | - Hiroshi Naganuma
- Department of Applied Physics, Graduate School of Engineering, Tohoku University, Sendai, 980-8579, Japan.,Unité Mixte de Physique, CNRS, Thales, Univ. Paris-Sud, Université Paris-Saclay, 91767, Palaiseau, France
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