251
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Janolin PE, Anokhin AS, Gui Z, Mukhortov VM, Golovko YI, Guiblin N, Ravy S, El Marssi M, Yuzyuk YI, Bellaiche L, Dkhil B. Strain engineering of perovskite thin films using a single substrate. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2014; 26:292201. [PMID: 24961271 DOI: 10.1088/0953-8984/26/29/292201] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Combining temperature-dependent x-ray diffraction, Raman spectroscopy and first-principles-based effective Hamiltonian calculations, we show that varying the thickness of (Ba0.8Sr0.2)TiO3 (BST) thin films deposited on the same single substrate (namely, MgO) enables us to change not only the magnitude but also the sign of the misfit strain. Such previously overlooked control of the strain allows several properties of these films (e.g. Curie temperature, symmetry of ferroelectric phases, dielectric response) to be tuned and even optimized. Surprisingly, such desired control of the strain (and of the resulting properties) originates from an effect that is commonly believed to be detrimental to functionalities of films, namely the existence of misfit dislocations. The present study therefore provides a novel route to strain engineering, as well as leading us to revisit common beliefs.
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Affiliation(s)
- P-E Janolin
- Laboratoire Structures, Propriétés et Modélisation des Solides, UMR CNRS-École Centrale Paris, Grande Voie des Vignes, 92295 Châtenay-Malabry Cedex, France
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252
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Seidel J, Trassin M, Zhang Y, Maksymovych P, Uhlig T, Milde P, Köhler D, Baddorf AP, Kalinin SV, Eng LM, Pan X, Ramesh R. Electronic properties of isosymmetric phase boundaries in highly strained Ca-Doped BiFeO₃. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2014; 26:4376-4380. [PMID: 24729350 DOI: 10.1002/adma.201400557] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/04/2014] [Revised: 03/19/2014] [Indexed: 06/03/2023]
Affiliation(s)
- Jan Seidel
- School of Materials Science and Engineering, University of New South Wales, Sydney, NSW, 2052, Australia; Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA; Department of Physics, University of California, Berkeley, Berkeley, CA, 94720, USA
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253
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Kuo HH, Chen L, Ji Y, Liu HJ, Chen LQ, Chu YH. Tuning phase stability of complex oxide nanocrystals via conjugation. NANO LETTERS 2014; 14:3314-3320. [PMID: 24871683 DOI: 10.1021/nl500744h] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Nanocrystals (NCs) attract tremendous research interests because of their unique properties to meet the demands of functionalities. To date, hybrid NCs with multiple components are developed to meet the rising demands that could be very difficult, or even impossible to be achieved by single-component NCs. Tuning properties by strain via conjugation could be an alternative solution. Strain engineering has been discovered and widely applied to many thin-film materials for tuning physical properties. Then, there is a further question to be addressed in this study: can we take the advantages we have learned in heteroepitaxy of thin films and transfer that into the NC conjugation? In order to demonstrate this possibility, we investigated NC conjugation of BiFeO3 and LaAlO3. We found that change in either LaAlO3-NC or BiFeO3-NC size would change the stability of rhombohedral-to-tetragonal phase transition. The present results show that strain engineering is possible to be realized in not only thin film but also NC conjugation. The same concept should be applicable to other complex oxide systems in order to broaden their practical applications for the rising demands of multifunctionalities.
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Affiliation(s)
- Ho-Hung Kuo
- Department of Materials Science and Engineering, National Chiao Tung University , Hsinchu 30010, Taiwan
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254
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Zhu Y, Liu P, Yu R, Hsieh YH, Ke D, Chu YH, Zhan Q. Orientation-tuning in self-assembled heterostructures induced by a buffer layer. NANOSCALE 2014; 6:5126-5131. [PMID: 24727857 DOI: 10.1039/c3nr06664a] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Anisotropic nano-plate structures in self-assembled perovskite-spinel thin films, BiFeO3-NiFe2O4 and BiFeO3-CoFe2O4, which were deposited on (001)c SrRuO3/SrTiO3 and DyScO3 substrates, respectively, have been demonstrated using transmission electron microscopy combined with strain analysis. Unlike the unitary cube-on-cube orientation relationship reported widely, the growth direction of the CoFe2O4 and NiFe2O4 plates was tuned to [011]c while the BiFeO3 matrix kept [001]c in both systems. In particular, a thin stress-sensitive BiFeO3 buffer layer between the spinel nanostructure and the substrate was introduced for providing a complex strain state in both film systems. The novel orientation tuning and the pattern configuration of the heterostructures are mainly attributed to the strain imposed on the films and the anisotropic ledge growth mechanism of spinels.
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Affiliation(s)
- Yuanmin Zhu
- School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, China.
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255
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Abstract
Here we present a simple and fast method to reliably image polarization charges using charge gradient microscopy (CGM). We collected the current from the grounded CGM probe while scanning a periodically poled lithium niobate single crystal and single-crystal LiTaO3 thin film on the Cr electrode. We observed current signals at the domains and domain walls originating from the displacement current and the relocation or removal of surface charges, which enabled us to visualize the ferroelectric domains at a scan frequency above 78 Hz over 10 μm. We envision that CGM can be used in high-speed ferroelectric domain imaging and piezoelectric energy-harvesting devices.
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256
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Yang CH, Kan D, Takeuchi I, Nagarajan V, Seidel J. Doping BiFeO3: approaches and enhanced functionality. Phys Chem Chem Phys 2014; 14:15953-62. [PMID: 23108014 DOI: 10.1039/c2cp43082g] [Citation(s) in RCA: 77] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
BiFeO(3) is one of the most studied multiferroic materials. Both its magnetic and ferroelectric properties can be influenced by doping. A large body of work on the doped material has been presented in the past couple of years. In this paper we provide a perspective on general doping concepts and their impact on the material's functionality.
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Affiliation(s)
- Chan-Ho Yang
- Department of Physics, Korea Advanced Institute of Science and Technology, Daejeon, Republic of Korea
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257
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Fan Z, Wang J, Sullivan MB, Huan A, Singh DJ, Ong KP. Structural instability of epitaxial (001) BiFeO₃ thin films under tensile strain. Sci Rep 2014; 4:4631. [PMID: 24717537 PMCID: PMC3982161 DOI: 10.1038/srep04631] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2013] [Accepted: 03/24/2014] [Indexed: 11/25/2022] Open
Abstract
We explore BiFeO3 under tensile strain using first-principles calculations. We find that the actual structures are more complex than what had been previously thought, and that there is a strong shear deformation type structural instability which modifies the properties. Specifically, we find that normal tensile strain leads to structural instabilities with a large induced shear deformation in (001) BiFeO3 thin films. These induced shear deformations in (001) BiFeO3 thin films under tension stabilize the (001) BiFeO3 thin films and lead to Cc and Ima2 phases that are more stable than the Pmc21 phase at high tensile strain. The induced shear deformation shifts the Cc to Ima2 phase transition towards lower tensile strain region (~1% less), prevents monoclinic tilt and oxygen octahedral tilts, and increases the ferroelectric polarization. The induced shear deformation also strongly affects the electronic structure. The results are discussed in relation to growth of BiFeO3 thin films on cubic and tetragonal substrates involving high levels of tensile strain.
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Affiliation(s)
- Zhen Fan
- Department of Materials Science and Engineering, National University of Singapore, 9 Engineering Drive 1, 117576, Singapore
| | - John Wang
- Department of Materials Science and Engineering, National University of Singapore, 9 Engineering Drive 1, 117576, Singapore
| | - Michael B. Sullivan
- Institute of High Performance Computing, Agency of Science, Technology and Research (A*STAR), 1 Fusionopolis Way, 138632, Singapore
| | - Alfred Huan
- Institute of High Performance Computing, Agency of Science, Technology and Research (A*STAR), 1 Fusionopolis Way, 138632, Singapore
| | - David J. Singh
- Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6056, USA
| | - Khuong P. Ong
- Institute of High Performance Computing, Agency of Science, Technology and Research (A*STAR), 1 Fusionopolis Way, 138632, Singapore
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258
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Wang JJ, Hu JM, Yang TN, Feng M, Zhang JX, Chen LQ, Nan CW. Effect of strain on voltage-controlled magnetism in BiFeO₃-based heterostructures. Sci Rep 2014; 4:4553. [PMID: 24686503 PMCID: PMC3971450 DOI: 10.1038/srep04553] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2014] [Accepted: 03/14/2014] [Indexed: 11/24/2022] Open
Abstract
Voltage-modulated magnetism in magnetic/BiFeO3 heterostructures can be driven by a combination of the intrinsic ferroelectric-antiferromagnetic coupling in BiFeO3 and the antiferromagnetic-ferromagnetic exchange interaction across the heterointerface. However, ferroelectric BiFeO3 film is also ferroelastic, thus it is possible to generate voltage-induced strain in BiFeO3 that could be applied onto the magnetic layer across the heterointerface and modulate magnetism through magnetoelastic coupling. Here, we investigated, using phase-field simulations, the role of strain in voltage-controlled magnetism for these BiFeO3-based heterostructures. It is predicted, under certain condition, coexistence of strain and exchange interaction will result in a pure voltage-driven 180° magnetization reversal in BiFeO3-based heterostructures.
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Affiliation(s)
- J J Wang
- 1] State Key Lab of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing, 100084, China [2]
| | - J M Hu
- 1] State Key Lab of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing, 100084, China [2] Department of Materials Science and Engineering, The Pennsylvania State University, University Park, Pennsylvania, 16802, USA [3]
| | - T N Yang
- Department of Materials Science and Engineering, The Pennsylvania State University, University Park, Pennsylvania, 16802, USA
| | - M Feng
- State Key Lab of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing, 100084, China
| | - J X Zhang
- Department of Physics, Beijing Normal University, Beijing, 100875, China
| | - L Q Chen
- 1] State Key Lab of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing, 100084, China [2] Department of Materials Science and Engineering, The Pennsylvania State University, University Park, Pennsylvania, 16802, USA
| | - C W Nan
- State Key Lab of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing, 100084, China
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259
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Ramesh R. Electric field control of ferromagnetism using multi-ferroics: the bismuth ferrite story. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2014; 372:20120437. [PMID: 24421371 DOI: 10.1098/rsta.2012.0437] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Since the re-emergence of multi-ferroics and magnetoelectrics almost a decade ago, bismuth ferrite has been among the most heavily studied model system. It is a multi-ferroic with robust ferroelectricity and antiferromagnetism, in conjunction with weak ferromagnetism arising primarily from spin-orbit coupling effects. This material system has generated a significant amount of discussion in the community, because many of the physical properties measured in thin films are different from the bulk. This paper summarizes some of the key observations in this versatile materials system, with a particular focus on thin films, heterostructures and interfacial phenomena.
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Affiliation(s)
- R Ramesh
- Departments of Materials Science and Engineering and Physics, University of California, , Berkeley, CA 94720, USA
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260
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Herklotz A, Biegalski MD, Christen HM, Guo EJ, Nenkov K, Rata AD, Schultz L, Dörr K. Strain response of magnetic order in perovskite-type oxide films. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2014; 372:20120441. [PMID: 24421374 DOI: 10.1098/rsta.2012.0441] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
The role of elastic strain for magnetoelectric materials and devices is twofold. It can induce ferroic orders in thin films of otherwise non-ferroic materials. On the other hand, it provides the most exploited coupling mechanism in two-phase magnetoelectric materials and devices today. Complex oxide films (perovskites, spinels) are promising for both routes. The strain control of magnetic order in complex oxide films is a young research field, and few ab initio simulations are available for magnetic order in dependence on lattice parameters and lattice symmetry. Here, an experimental approach for the evaluation of how elastic strain in thin epitaxial films alters their magnetic order is introduced. The magnetic films are grown epitaxially in strain states controlled by buffer layers onto piezoelectric substrates of 0.72Pb(Mg1/3Nb2/3)O3-0.28PbTiO3(001). As an example, the strain dependence of the ordered magnetic moment of SrRuO3 has been investigated. At a tensile strain level of approximately 1%, SrRuO3 is tetragonal, and biaxial elastic strain induces a pronounced suppression of the ordered magnetic moment. As a second example, a strain-driven transition from a ferromagnetic to a magnetically disordered phase has been observed in epitaxial La0.8Sr0.2CoO3 films.
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Affiliation(s)
- A Herklotz
- Institute for Physics, Martin Luther University Halle-Wittenberg, , Halle 06099, Germany
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261
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Zhao YJ, Yin ZG, Zhang XW, Fu Z, Sun BJ, Wang JX, Wu JL. Heteroepitaxy of tetragonal BiFeO(3) on hexagonal sapphire(0001). ACS APPLIED MATERIALS & INTERFACES 2014; 6:2639-2646. [PMID: 24467526 DOI: 10.1021/am405115y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Highly elongated BiFeO3 is epitaxially grown on hexagonal sapphire(0001) substrate within a rather narrow synthesis window. Both X-ray reciprocal space maps and Raman characterizations reveal that it is of true tetragonal symmetry but not the commonly observed MC type monoclinic structure. The tetragonal BiFeO3 film exhibits an island growth mode, with the island edges oriented parallel to the ⟨10-10⟩ and ⟨12-30⟩ directions of the sapphire substrate. With increasing deposition time, a transition from square island to elongated island and then to a continuous film is observed. The metastable tetragonal phase can remain on the substrate without relaxation to the thermally stable rhombohedral phase up to a critical thickness of 450 nm, providing an exciting opportunity for practicable lead-free ferroelectrics. These results facilitate a better understanding of the phase stability of BiFeO3 polymorphs and enrich the knowledge about the heteroepitaxial growth mechanism of functional oxides on symmetry-mismatched substrates.
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Affiliation(s)
- Y J Zhao
- Key Lab of Semiconductor Materials Science and ‡State Key Laboratory of Solid-State Lighting, Institute of Semiconductors, Chinese Academy of Sciences , Beijing 100083, People's Republic of China
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262
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Aso R, Kan D, Shimakawa Y, Kurata H. Atomic level observation of octahedral distortions at the perovskite oxide heterointerface. Sci Rep 2014; 3:2214. [PMID: 23856752 PMCID: PMC3712312 DOI: 10.1038/srep02214] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2013] [Accepted: 07/01/2013] [Indexed: 11/09/2022] Open
Abstract
For perovskite oxides, ABO3, slight octahedral distortions have close links to functional properties. While perovskite oxide heterostructures offer a good platform for controlling functionalities, atomistic understanding of octahedral distortion at the interface has been a challenge as it requires precise measurements of the oxygen atomic positions. Here we demonstrate an approach to clarify distortions at an atomic level using annular bright-field imaging in aberration-corrected scanning transmission electron microscopy, which provides precise mappings of cation and oxygen atomic positions from distortion-minimized images. This technique revealed significant distortions of RuO6 and ScO6 octahedra at the heterointerface between a SrRuO3 film and a GdScO3 substrate. We also found that structural mismatch was relieved within only four unit cells near the interface by shifting the oxygen atomic positions to accommodate octahedral tilt angle mismatch. The present results underscore the critical role of the oxygen atom in the octahedral connectivity at the perovskite oxide heterointerface.
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Affiliation(s)
- Ryotaro Aso
- Institute for Chemical Research, Kyoto University, Uji, Kyoto, Japan
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263
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Yang Y, Iñiguez J, Mao AJ, Bellaiche L. Prediction of a novel magnetoelectric switching mechanism in multiferroics. PHYSICAL REVIEW LETTERS 2014; 112:057202. [PMID: 24580626 DOI: 10.1103/physrevlett.112.057202] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2013] [Indexed: 06/03/2023]
Abstract
We report a first-principles study of the recently predicted Pmc21 phase of the multiferroic BiFeO3 material, revealing a novel magnetoelectric effect that makes it possible to control magnetism with an electric field. The effect can be viewed as a two-step process: Switching the polarization first results in the change of the sense of the rotation of the oxygen octahedra, which in turn induces the switching of the secondary magnetic order parameter. The first step is governed by an original trilinear-coupling energy between polarization, octahedral tilting, and an antiferroelectric distortion. The second step is controlled by another trilinear coupling, this one involving the predominant and secondary magnetic orders as well as the oxygen octahedral tilting. In contrast with other trilinear-coupling effects in the literature, the present ones occur in a simple ABO3 perovskite and involve a large polarization.
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Affiliation(s)
- Yurong Yang
- Physics Department and Institute for Nanoscience and Engineering, University of Arkansas, Fayetteville, Arkansas 72701, USA and Physics Department, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China
| | - Jorge Iñiguez
- Institut de Ciència de Materials de Barcelona (ICMAB-CSIC), Campus UAB, 08193 Bellaterra, Spain
| | - Ai-Jie Mao
- Institute of Atomic and Molecular Physics, Sichuan University, Chengdu 610065, China
| | - L Bellaiche
- Physics Department and Institute for Nanoscience and Engineering, University of Arkansas, Fayetteville, Arkansas 72701, USA
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264
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Franzbach DJ, Seo YH, Studer AJ, Zhang Y, Glaum J, Daniels JE, Koruza J, Benčan A, Malič B, Webber KG. Electric-field-induced phase transitions in co-doped Pb(Zr 1-xTi x)O 3 at the morphotropic phase boundary. SCIENCE AND TECHNOLOGY OF ADVANCED MATERIALS 2014; 15:015010. [PMID: 27877652 PMCID: PMC5090613 DOI: 10.1088/1468-6996/15/1/015010] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/12/2013] [Revised: 02/28/2014] [Accepted: 02/03/2014] [Indexed: 06/04/2023]
Abstract
The strain- and polarization-electric field behavior was characterized at room temperature for Pb0.98Ba0.01(Zr1-x Ti x )0.98Nb0.02O3, 0.40 ⩽ x ⩽ 0.60. The investigated compositions were located in the vicinity of the morphotropic phase boundary, giving insight into the influence of crystal structure on the hysteretic ferroelectric behavior. The remanent strain of particular compositions is shown to be larger than theoretically allowed by ferroelectric switching alone, indicating the presence of additional remanent strain mechanisms. A phenomenological free energy analysis was used to simulate the effect of an applied electric field on the initial equilibrium phase. It is shown that electric-field-induced phase transitions in polycrystalline ferroelectrics can account for the experimental observations. The experimental and simulation results are contrasted to neutron diffraction measurements performed on representative compositions in the virgin and remanent states.
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Affiliation(s)
- Daniel J Franzbach
- Institute of Materials Science, Technische Universität Darmstadt, D-64287, Darmstadt, Germany
- Graduate School of Computational Engineering, Technische Universität Darmstadt, D-64287, Darmstadt, Germany
| | - Yo-Han Seo
- Institute of Materials Science, Technische Universität Darmstadt, D-64287, Darmstadt, Germany
| | - Andrew J Studer
- Australian Nuclear Science and Technology Organisation, Locked Bag 2001, Kirrawee DC, NSW 2232, Australia
| | - Yichi Zhang
- School of Materials Science and Engineering, University of New South Wales, Sydney, NSW 2052, Australia
| | - Julia Glaum
- School of Materials Science and Engineering, University of New South Wales, Sydney, NSW 2052, Australia
| | - John E Daniels
- School of Materials Science and Engineering, University of New South Wales, Sydney, NSW 2052, Australia
| | - Jurij Koruza
- Institute of Materials Science, Technische Universität Darmstadt, D-64287, Darmstadt, Germany
- Jožef Stefan Institute, Jamova cesta 39, Si-1000, Ljubljana, Slovenia
| | - Andreja Benčan
- Jožef Stefan Institute, Jamova cesta 39, Si-1000, Ljubljana, Slovenia
| | - Barbara Malič
- Jožef Stefan Institute, Jamova cesta 39, Si-1000, Ljubljana, Slovenia
| | - Kyle G Webber
- Institute of Materials Science, Technische Universität Darmstadt, D-64287, Darmstadt, Germany
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265
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Moon EJ, Xie Y, Laird ED, Keavney DJ, Li CY, May SJ. Fluorination of Epitaxial Oxides: Synthesis of Perovskite Oxyfluoride Thin Films. J Am Chem Soc 2014; 136:2224-7. [DOI: 10.1021/ja410954z] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Eun Ju Moon
- Department
of Materials Science and Engineering, Drexel University, Philadelphia, Pennsylvania 19104, United States
| | - Yujun Xie
- Department
of Materials Science and Engineering, Drexel University, Philadelphia, Pennsylvania 19104, United States
| | - Eric D. Laird
- Department
of Materials Science and Engineering, Drexel University, Philadelphia, Pennsylvania 19104, United States
| | - David J. Keavney
- X-ray
Sciences Division, Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439, United States
| | - Christopher Y. Li
- Department
of Materials Science and Engineering, Drexel University, Philadelphia, Pennsylvania 19104, United States
| | - Steven J. May
- Department
of Materials Science and Engineering, Drexel University, Philadelphia, Pennsylvania 19104, United States
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266
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Tu YC, Chang CY, Wu MC, Shyue JJ, Su WF. BiFeO3/YSZ bilayer electrolyte for low temperature solid oxide fuel cell. RSC Adv 2014. [DOI: 10.1039/c4ra01862a] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Highly crystalline perovskite BiFeO3 is obtained by a facile solution method. We have reported that the YSZ/BFO electrolyte with 17 μm/30 μm thickness, respectively, showed a maximum power density of 165 mW cm−2 and open-circuit voltage of 0.75 V at 650 °C.
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Affiliation(s)
- Yu-Chieh Tu
- Department of Materials Science and Engineering
- National Taiwan University
- Taipei 10617, Taiwan
| | - Chun-Yu Chang
- Department of Materials Science and Engineering
- National Taiwan University
- Taipei 10617, Taiwan
| | - Ming-Chung Wu
- Department of Chemical and Materials Engineering
- Chang Gung University
- Taoyuan 333-02, Taiwan
| | - Jing-Jong Shyue
- Department of Materials Science and Engineering
- National Taiwan University
- Taipei 10617, Taiwan
- Research Center for Applied Sciences
- Academia Sinica
| | - Wei-Fang Su
- Department of Materials Science and Engineering
- National Taiwan University
- Taipei 10617, Taiwan
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267
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Planes A, Mañosa L. Shape-memory materials: Nanoscale oxides shape up. NATURE MATERIALS 2014; 13:6-8. [PMID: 24343511 DOI: 10.1038/nmat3844] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Affiliation(s)
- Antoni Planes
- Departament d'Estructura i Constituents de la Matèria, University of Barcelona, Diagonal 647, 08028 Barcelona, Catalonia, Spain
| | - Lluís Mañosa
- Departament d'Estructura i Constituents de la Matèria, University of Barcelona, Diagonal 647, 08028 Barcelona, Catalonia, Spain
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268
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Masys Š, Jonauskas V. A first-principles study of structural and elastic properties of bulk SrRuO3. J Chem Phys 2013; 139:224705. [PMID: 24329080 DOI: 10.1063/1.4840435] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Š Masys
- Institute of Theoretical Physics and Astronomy, Vilnius University, A. Goštauto Street 12, LT-01108 Vilnius, Lithuania
| | - V Jonauskas
- Institute of Theoretical Physics and Astronomy, Vilnius University, A. Goštauto Street 12, LT-01108 Vilnius, Lithuania
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269
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Zhang J, Ke X, Gou G, Seidel J, Xiang B, Yu P, Liang WI, Minor AM, Chu YH, Van Tendeloo G, Ren X, Ramesh R. A nanoscale shape memory oxide. Nat Commun 2013; 4:2768. [DOI: 10.1038/ncomms3768] [Citation(s) in RCA: 83] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2013] [Accepted: 10/14/2013] [Indexed: 11/09/2022] Open
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270
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Li L, Gao P, Nelson CT, Jokisaari JR, Zhang Y, Kim SJ, Melville A, Adamo C, Schlom DG, Pan X. Atomic scale structure changes induced by charged domain walls in ferroelectric materials. NANO LETTERS 2013; 13:5218-5223. [PMID: 24070735 DOI: 10.1021/nl402651r] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Charged domain walls (CDWs) are of significant scientific and technological importance as they have been shown to play a critical role in controlling the switching mechanism and electric, photoelectric, and piezoelectric properties of ferroelectric materials. The atomic scale structure and properties of CDWs, which are critical for understanding the emergent properties, have, however, been rarely explored. In this work, using a spherical-aberration-corrected transmission electron microscope with subangstrom resolution, we have found that the polarization bound charge of the CDW in rhombohedral-like BiFeO3 thin films not only induces the formation of a tetragonal-like crystal structure at the CDW but also stabilizes unexpected nanosized domains with new polarization states and unconventional domain walls. These findings provide new insights on the effects of bound charge on ferroelectric domain structures and are critical for understanding the electrical switching in ferroelectric thin films as well as in memory devices.
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Affiliation(s)
- Linze Li
- Department of Materials Science and Engineering, University of Michigan , Ann Arbor, Michigan 48109, United States
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271
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Beekman C, Siemons W, Ward TZ, Chi M, Howe J, Biegalski MD, Balke N, Maksymovych P, Farrar AK, Romero JB, Gao P, Pan XQ, Tenne DA, Christen HM. Phase transitions, phase coexistence, and piezoelectric switching behavior in highly strained BiFeO(3) films. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2013; 25:5561-7. [PMID: 23847158 DOI: 10.1002/adma.201302066] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/07/2013] [Indexed: 05/12/2023]
Abstract
Highly strained BiFeO3 films transition into a true tetragonal state at 430 °C but remain polar to much higher temperatures (∼800 °C). Piezoelectric switching is only possible up to 300 °C, i.e., at temperatures for which strain stabilizes the stripe-like coexistence of multiple polymorphs.
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Affiliation(s)
- C Beekman
- Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
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272
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Sando D, Agbelele A, Rahmedov D, Liu J, Rovillain P, Toulouse C, Infante IC, Pyatakov AP, Fusil S, Jacquet E, Carrétéro C, Deranlot C, Lisenkov S, Wang D, Le Breton JM, Cazayous M, Sacuto A, Juraszek J, Zvezdin AK, Bellaiche L, Dkhil B, Barthélémy A, Bibes M. Crafting the magnonic and spintronic response of BiFeO3 films by epitaxial strain. NATURE MATERIALS 2013; 12:641-6. [PMID: 23624631 DOI: 10.1038/nmat3629] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/22/2012] [Accepted: 03/12/2013] [Indexed: 05/05/2023]
Abstract
Multiferroics are compounds that show ferroelectricity and magnetism. BiFeO3, by far the most studied, has outstanding ferroelectric properties, a cycloidal magnetic order in the bulk, and many unexpected virtues such as conductive domain walls or a low bandgap of interest for photovoltaics. Although this flurry of properties makes BiFeO3 a paradigmatic multifunctional material, most are related to its ferroelectric character, and its other ferroic property--antiferromagnetism--has not been investigated extensively, especially in thin films. Here we bring insight into the rich spin physics of BiFeO3 in a detailed study of the static and dynamic magnetic response of strain-engineered films. Using Mössbauer and Raman spectroscopies combined with Landau-Ginzburg theory and effective Hamiltonian calculations, we show that the bulk-like cycloidal spin modulation that exists at low compressive strain is driven towards pseudo-collinear antiferromagnetism at high strain, both tensile and compressive. For moderate tensile strain we also predict and observe indications of a new cycloid. Accordingly, we find that the magnonic response is entirely modified, with low-energy magnon modes being suppressed as strain increases. Finally, we reveal that strain progressively drives the average spin angle from in-plane to out-of-plane, a property we use to tune the exchange bias and giant-magnetoresistive response of spin valves.
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Affiliation(s)
- D Sando
- Unité Mixte de Physique CNRS/Thales, 1 av. Fresnel, 91767 Palaiseau & Université Paris-Sud, 91405 Orsay, France
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273
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Saha D, Ranjan R, Swain D, Narayana C, Row TNG. An unusual temperature induced isostructural phase transition in a scheelite, Li(0.5)Ce(0.5)MoO4. Dalton Trans 2013; 42:7672-8. [PMID: 23538608 DOI: 10.1039/c3dt33033h] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
High resolution synchrotron X-ray diffraction, dielectric and Raman scattering study of a scheelite compound Li0.5Ce0.5MoO4 (LCM) revealed that it transforms to a self similar structure above 400 °C. The thermally induced isostructural phase transition (IPT), a phenomenon which has rarely been reported in the literature, is preceded by partial softening of the zone centre phonons followed by their hardening above the IPT transition temperature. The high temperature isostructural phase, which exhibits expanded lattice parameters and cell volume, nucleates and grows in the low temperature matrix over a very wide temperature range. Both the phases show nearly identical thermal expansion suggesting similarities in symmetry, unaltered coordination environments around the atoms across the transition.
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Affiliation(s)
- Dipankar Saha
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Bangalore 560 012, India
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274
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Kim YM, Kumar A, Hatt A, Morozovska AN, Tselev A, Biegalski MD, Ivanov I, Eliseev EA, Pennycook SJ, Rondinelli JM, Kalinin SV, Borisevich AY. Interplay of octahedral tilts and polar order in BiFeO3 films. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2013; 25:2497-2504. [PMID: 23505214 DOI: 10.1002/adma.201204584] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/05/2012] [Revised: 01/04/2013] [Indexed: 06/01/2023]
Abstract
Heterointerface stabilization of a distinct nonpolar BiFeO3 phase occurs simultaneously with changes in octahedral tilts. The resulting phase arises via suppression of polarization by a structural order parameter and can thus be identified as anti-ferroelectric (Fe displacements - bottom panel). The phase is metastable and can be switched into a polar ferroelectric state (top panel) under an applied electric bias.
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Affiliation(s)
- Young-Min Kim
- Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
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275
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Guo JL, Chiou YD, Liang WI, Liu HJ, Chen YJ, Kuo WC, Tsai CY, Tsai KA, Kuo HH, Hsieh WF, Juang JY, Hsu YJ, Lin HJ, Chen CT, Liao XP, Shi B, Chu YH. Complex oxide-noble metal conjugated nanoparticles. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2013; 25:2040-4. [PMID: 23427105 DOI: 10.1002/adma.201204582] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/05/2012] [Revised: 11/29/2012] [Indexed: 05/20/2023]
Abstract
Hybrid nanoparticles (NPs) composed of multiple components offer new opportunities for next-generation materials. In this study, a paradigm for the noble metal/ternary complex oxide hybrid NPs is reported by adopting pulsed laser ablation in liquids. As model hybrids, gold-spinel heterodimer (Au-CoFe2O4) and gold-pervoskite heterodimer (Au-SrTiO3) NPs are investigated. This work has demonstrated the diverse playgroup of NP conjugation enlarged by complex oxides.
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Affiliation(s)
- Jun-Ling Guo
- Department of Materials Science and Engineering, National Chiao Tung University, HsinChu, Taiwan, ROC
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276
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Shimizu T, Suwama D, Taniguchi H, Taniyama T, Itoh M. Comparative study of phase transitions in BaTiO3 thin films grown on (001)- and (110)-oriented SrTiO3 substrate. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2013; 25:132001. [PMID: 23420535 DOI: 10.1088/0953-8984/25/13/132001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
An increase of the Curie temperature, TC, was demonstrated for BaTiO3 (BTO) epitaxial thin films grown by a pulsed laser deposition technique on (001) and (110) SrTiO3 (STO) substrates. The T(C) values for the BTO films on (001) and (110) STO were determined, from the temperature dependence of the lattice constants, to be 720 and 550 K, respectively, both of which are higher than that for bulk BTO. The increase of T(C) for the film on (001) BTO is suggested to stem from a large tetragonal deformation with a tetragonality of ~1.02 due to a two-dimensional clamping effect, which persists even in the paraelectric phase. That for the (110) BTO film, on the other hand, could be caused by a one-dimensional clamping effect due to uniaxial strain.
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Affiliation(s)
- Takao Shimizu
- Materials and Structures Laboratory, Tokyo Institute of Technology, Yokohama 226-8503, Japan
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277
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Liu S, Grinberg I, Rappe AM. Development of a bond-valence based interatomic potential for BiFeO3 for accurate molecular dynamics simulations. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2013; 25:102202. [PMID: 23399759 DOI: 10.1088/0953-8984/25/10/102202] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
We present an atomistic potential for BiFeO(3) based on the principles of bond-valence (BV) and bond-valence vector (BVV) conservation. The validity of this model potential is tested for both canonical ensemble (NVT) and isobaric-isothermal ensemble (NPT) molecular dynamics (MD) simulations. The model reproduces the ferroelectric-to-paraelectric phase transition in both NVT and NPT MD simulations and the temperature dependence of the local structure in BiFeO(3). The calculated domain wall energies for 71°, 109°and 180° walls agree well with density functional theory results. The success of our simple model potential for BiFeO(3) indicates that BV and BVV conservation provides a firm basis for the development of accurate atomistic potentials for complex oxides.
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Affiliation(s)
- Shi Liu
- The Makineni Theoretical Laboratories, Department of Chemistry, University of Pennsylvania, Philadelphia, PA 19104-6323, USA
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278
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Dong SN, Yao YP, Li JQ, Song YJ, Liu YK, Li XG. Room temperature multiferroicity in Bi(4.2)K(0.8)Fe(2)O(9+δ). Sci Rep 2013; 3:1245. [PMID: 23409236 PMCID: PMC3570784 DOI: 10.1038/srep01245] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2012] [Accepted: 01/22/2013] [Indexed: 11/29/2022] Open
Abstract
Magnetoelectric multiferroics are materials that have coupled magnetic and electric dipole orders, which can bring novel physical phenomena and offer possibilities for new device functions. In this report, single-crystalline Bi4.2K0.8Fe2O9+δ nanobelts which are isostructural with the high-temperature superconductor Bi2Sr2CaCu2O8+δ are successfully grown by a hydrothermal method. The regular stacking of the rock salt slabs and the BiFeO3-like perovskite blocks along the c axis of the crystal makes the Bi4.2K0.8Fe2O9+δ nanobelts have a natural magnetoelectric–dielectric superlattice structure. The most striking result is that the bulk material made of the Bi4.2K0.8Fe2O9+δ nanobelts is of multiferroicity near room temperature accompanied with a structure anomaly. When an external magnetic field is applied, the electric polarization is greatly suppressed, and correspondingly, a large negative magnetocapacitance coefficient is observed around 270 K possibly due to the magnetoelectric coupling effect. Our result provides contributions to the development of single phase multiferroics.
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Affiliation(s)
- Si-Ning Dong
- Hefei National Laboratory for Physical Sciences at Microscale, Department of Physics, CAS Key Lab Mat Energy Convers, University of Science and Technology of China , Hefei 230026, PR China
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279
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Yao R, Cao C, Zheng C, Lei Q. Lattice mismatch induced strained phase for magnetization, exchange bias and polarization in multiferroic BiFeO3. RSC Adv 2013. [DOI: 10.1039/c3ra42790k] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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280
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Yang JC, He Q, Suresha SJ, Kuo CY, Peng CY, Haislmaier RC, Motyka MA, Sheng G, Adamo C, Lin HJ, Hu Z, Chang L, Tjeng LH, Arenholz E, Podraza NJ, Bernhagen M, Uecker R, Schlom DG, Gopalan V, Chen LQ, Chen CT, Ramesh R, Chu YH. Orthorhombic BiFeO3. PHYSICAL REVIEW LETTERS 2012; 109:247606. [PMID: 23368382 DOI: 10.1103/physrevlett.109.247606] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2012] [Revised: 09/07/2012] [Indexed: 05/12/2023]
Abstract
A new orthorhombic phase of the multiferroic BiFeO3 has been created via strain engineering by growing it on a NdScO(3)(110)(o) substrate. The tensile-strained orthorhombic BiFeO3 phase is ferroelectric and antiferromagnetic at room temperature. A combination of nonlinear optical second harmonic generation and piezoresponse force microscopy revealed that the ferroelectric polarization in the orthorhombic phase is along the in-plane {110}(pc) directions. In addition, the corresponding rotation of the antiferromagnetic axis in this new phase was observed using x-ray linear dichroism.
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Affiliation(s)
- J C Yang
- Department of Materials Science and Engineering, National Chiao Tung University, Hsinchu 300, Taiwan
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281
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Yu P, Chu YH, Ramesh R. Emergent phenomena at multiferroic heterointerfaces. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2012; 370:4856-4871. [PMID: 22987032 DOI: 10.1098/rsta.2012.0199] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
The coupling and reconstruction of electronic degrees of freedom (such as charge, spin and orbital) at a heterointerface can lead to unexpected and exotic states of matter. In this study, using model systems consisting of multiferroic BiFeO(3) and ferromagnetic La(0.7)Sr(0.3)MnO(3), we review the current understanding of a novel interfacial magnetic state formed at the interface, and highlight some possible mechanisms responsible for this interesting phenomenon and identify open questions for future studies.
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Affiliation(s)
- P Yu
- Department of Physics, University of California, Berkeley, 94720, USA.
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282
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Zhang JX, Zeches RJ, He Q, Chu YH, Ramesh R. Nanoscale phase boundaries: a new twist to novel functionalities. NANOSCALE 2012; 4:6196-6204. [PMID: 22948414 DOI: 10.1039/c2nr31174g] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
In functional materials, nanoscale phase boundaries exhibit exotic phenomena that are notably absent in their parent phases. Over the past two decades, much of the research into complex oxides (such as cuprate superconductors, CMR manganites and relaxor ferroelectrics) has demonstrated the key role that nanoscale inhomogeneities play in controlling the electronic and/or ionic structure of these materials. One of the key characteristics in such systems is the strong susceptibility to external perturbations, such as magnetic, electric and mechanical fields. A direct consequence of the accommodation of a large number of cationic substitutions in complex oxides is the emergence of a number of physical phenomena from essentially the same crystal framework. Recently, multiferroic behavior, which is characterized by the co-existence and potential coupling of multiple ferroic order parameters, has captured considerable worldwide research interest. The perovskite, BiFeO(3), exhibits robust ferroelectricity coupled with antiferromagnetism at room temperature. A rather unique feature of this material system is its ability to "morph" its ground state when an external mechanical constraint is imposed on it. A particularly striking example is observed when a large (~4 to 5%) compressive strain is imposed on a thin film through the epitaxial constraint from the underlying substrate. Under these conditions, the ground state rhombohedral phase transforms into a tetragonal-like (or a derivative thereof) phase with a rather large unit cell (c/a ratio of ~1.26). When the epitaxial constraint is partially relaxed by increasing the film thickness, this tetragonal-like phase evolves into a "mixed-phase" state, consisting of a nanoscale admixture of the rhombohedral-like phase embedded in the tetragonal-like phase. Such a system gives us a new pathway to explore a variety of mechanical, magnetic and transport phenomena in constrained dimensions. This article reviews our progress to date in this direction and also captures some possible areas of future research. We use the electromechanical response and the magnetic properties as examples to illustrate that its novel functionalities are intrinsically due to the phase boundaries and not the constituent phases. The possible origin of the giant piezoelectric response and enhanced magnetic moment across the boundaries is proposed based on the flexoelectric and flexomagnetic effects.
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Affiliation(s)
- J X Zhang
- Department of Physics, University of California, Berkeley, California 94720, USA.
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283
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Vaz CAF. Electric field control of magnetism in multiferroic heterostructures. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2012; 24:333201. [PMID: 22824827 DOI: 10.1088/0953-8984/24/33/333201] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
We review the recent developments in the electric field control of magnetism in multiferroic heterostructures, which consist of heterogeneous materials systems where a magnetoelectric coupling is engineered between magnetic and ferroelectric components. The magnetoelectric coupling in these composite systems is interfacial in origin, and can arise from elastic strain, charge, and exchange bias interactions, with different characteristic responses and functionalities. Moreover, charge transport phenomena in multiferroic heterostructures, where both magnetic and ferroelectric order parameters are used to control charge transport, suggest new possibilities to control the conduction paths of the electron spin, with potential for device applications.
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Affiliation(s)
- C A F Vaz
- SwissFEL, Paul Scherrer Institut, Villigen PSI, Switzerland.
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284
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Wang D, Weerasinghe J, Bellaiche L. Atomistic molecular dynamic simulations of multiferroics. PHYSICAL REVIEW LETTERS 2012; 109:067203. [PMID: 23006300 DOI: 10.1103/physrevlett.109.067203] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2011] [Revised: 02/09/2012] [Indexed: 06/01/2023]
Abstract
A first-principles-based approach is developed to simulate dynamical properties, including complex permittivity and permeability in the GHz-THz range, of multiferroics at finite temperatures. It includes both structural degrees of freedom and magnetic moments as dynamic variables in Newtonian and Landau-Lifshitz-Gilbert (LLG) equations within molecular dynamics, respectively, with the couplings between these variables being incorporated. The use of a damping coefficient and of the fluctuation field in the LLG equations is required to obtain equilibrated magnetic properties at any temperature. No electromagnon is found in the spin-canted structure of BiFeO3. On the other hand, two magnons with very different frequencies are predicted via the use of this method. The smallest-in-frequency magnon corresponds to oscillations of the weak ferromagnetic vector in the basal plane being perpendicular to the polarization while the second magnon corresponds to magnetic dipoles going in and out of this basal plane. The large value of the frequency of this second magnon is caused by static couplings between magnetic dipoles with electric dipoles and oxygen octahedra tiltings.
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Affiliation(s)
- 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, China.
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285
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Yang Y, Ren W, Stengel M, Yan XH, Bellaiche L. Revisiting properties of ferroelectric and multiferroic thin films under tensile strain from first principles. PHYSICAL REVIEW LETTERS 2012; 109:057602. [PMID: 23006208 DOI: 10.1103/physrevlett.109.057602] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2012] [Indexed: 06/01/2023]
Abstract
First-principles calculations are performed to revisit properties of (001) epitaxial BiFeO(3) (BFO) and PbTiO(3) thin films under tensile strain. While these two films possess different ground states when experiencing no misfit strain, they both exhibit the same, previously unknown phase for tensile strains above ≃5% at T = 0 K. This novel state is of orthorhombic Pmc2(1) symmetry and is macroscopically characterized by a large in-plane polarization coexisting with oxygen octahedra tilting in-phase about the out-of-plane direction. On a microscopic point of view, this Pmc2(1) state exhibits short atomic bonds and zigzag cation displacement patterns, unlike conventional ferroelectric phases and typical domains. Such unusual inhomogeneous patterns originate from the coexistence of polar and antiferroelectric distortions having the same magnitude and lead BFO films to be the first known material for which orbital ordering coexists with a large polarization. Furthermore, this Pmc2(1) state is also found in other perovskite films under tensile strain, which emphasizes its generality.
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Affiliation(s)
- Yurong Yang
- Physics Department, University of Arkansas, Fayetteville, 72701, USA
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286
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You L, Chen Z, Zou X, Ding H, Chen W, Chen L, Yuan G, Wang J. Characterization and manipulation of mixed phase nanodomains in highly strained BiFeO3 thin films. ACS NANO 2012; 6:5388-5394. [PMID: 22591450 DOI: 10.1021/nn3012459] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
The novel strain-driven morphotropic phase boundary (MPB) in highly strained BiFeO(3) thin films is characterized by well-ordered mixed phase nanodomains (MPNs). Through scanning probe microscopy and synchrotron X-ray diffraction, eight structural variants of the MPNs are identified. Detailed polarization configurations within the MPNs are resolved using angular-dependent piezoelectric force microscopy. Guided by the obtained results, deterministic manipulation of the MPNs has been demonstrated by controlling the motion of the local probe. These findings are important for an in-depth understanding of the ultrahigh electromechanical response arising from phase transformation between competing phases, enabling future explorations on the electronic structure, magnetoelectricity, and other functionalities in this new MPB system.
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Affiliation(s)
- Lu You
- School of Materials Science and Engineering, Nanyang Technological University, Singapore, 639798
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287
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Chen YC, He Q, Chu FN, Huang YC, Chen JW, Liang WI, Vasudevan RK, Nagarajan V, Arenholz E, Kalinin SV, Chu YH. Electrical control of multiferroic orderings in mixed-phase BiFeO₃ films. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2012; 24:3070-3075. [PMID: 22570278 DOI: 10.1002/adma.201200463] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/02/2012] [Revised: 03/21/2012] [Indexed: 05/31/2023]
Affiliation(s)
- Yi-Chun Chen
- Department of Physics, National Cheng Kung University, Tainan 70101, Taiwan.
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288
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Zhang W, Yuan M, Wang X, Pan W, Wang CM, Ouyang J. Design and preparation of stress-free epitaxial BaTiO 3 polydomain films by RF magnetron sputtering. SCIENCE AND TECHNOLOGY OF ADVANCED MATERIALS 2012; 13:035006. [PMID: 27877494 PMCID: PMC5090283 DOI: 10.1088/1468-6996/13/3/035006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/02/2012] [Accepted: 05/03/2012] [Indexed: 05/30/2023]
Abstract
Domain structures of BaTiO3 thick films grown on (100) SrTiO3 single-crystal substrates were engineered using an RF magnetron sputtering deposition process. By tuning the sputtering power and cooling rate and using an off-axis sputtering technique to prepare conducting perovskite oxide bottom electrode with heteroepitaxial quality, we have deposited epitaxial tetragonal single-domain and polydomain BaTiO3 films with a self-assembled three-domain architecture. The electrical properties and microstructure of the BaTiO3 films were characterized, and a c/a1/a2 cellular polydomain structure was clearly observed in as-grown films by optical microscopy. Such a polydomain structure was a consequence of a complete relaxation of misfit stresses of the film. Engineering of this self-assembled microstructure has great potential in providing large, field-tunable pyroelectric and electromechanical responses in next-generation microelectronic devices and micro-electro-mechanical systems (MEMS).
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Affiliation(s)
- Wei Zhang
- Key Laboratory for Liquid–Solid Structural Evolution and Processing of Materials (Ministry of Education), Engineering Ceramics Key Laboratory of Shandong Province, School of Materials Science and Engineering, Shandong University, Jinan, Shandong 250061, China
| | - Meiling Yuan
- Key Laboratory for Liquid–Solid Structural Evolution and Processing of Materials (Ministry of Education), Engineering Ceramics Key Laboratory of Shandong Province, School of Materials Science and Engineering, Shandong University, Jinan, Shandong 250061, China
| | - Xianyang Wang
- Key Laboratory for Liquid–Solid Structural Evolution and Processing of Materials (Ministry of Education), Engineering Ceramics Key Laboratory of Shandong Province, School of Materials Science and Engineering, Shandong University, Jinan, Shandong 250061, China
| | - Wei Pan
- State Key Laboratory of New Ceramic and Fine Processing, Tsinghua University, Beijing 100084, China
| | - Chun-Ming Wang
- School of Physics, Shandong University, Jinan, Shandong 250010, China
| | - Jun Ouyang
- Key Laboratory for Liquid–Solid Structural Evolution and Processing of Materials (Ministry of Education), Engineering Ceramics Key Laboratory of Shandong Province, School of Materials Science and Engineering, Shandong University, Jinan, Shandong 250061, China
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289
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Wu JM, Xu C, Zhang Y, Wang ZL. Lead-free nanogenerator made from single ZnSnO3 microbelt. ACS NANO 2012; 6:4335-4340. [PMID: 22482511 DOI: 10.1021/nn300951d] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
We demonstrated a single-microbelt nanogenerator first made using a ZnSnO(3) microbelt that generated an output power of ∼3 nW under a compressive and releasing strain of 0.8-1%. The ZnSnO(3) nanobelts/microbelts were synthesized using a vapor transfer process at 1173 K. The X-ray diffraction pattern shows that the microbelts belong to ZnSnO(3) with rhombohedral structure. An individual ZnSnO(3) microbelt was bonded at its ends on a flexible polystyrene substrate as a nanogenerator, which gives an output voltage and current of 100 mV and 30 nA, respectively, corresponding to an energy conversion efficiency of 4.2-6.6% (based on 0.8-1% strain). Our results show that ZnSnO(3) microbelts are one of the highly promising materials for lead-free piezoelectric energy harvesting.
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Affiliation(s)
- Jyh Ming Wu
- Department of Materials Science and Engineering, Feng Chia University, Taichung 40724, Taiwan, Republic of China
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290
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Wu JM, Chen CY, Zhang Y, Chen KH, Yang Y, Hu Y, He JH, Wang ZL. Ultrahigh sensitive piezotronic strain sensors based on a ZnSnO3 nanowire/microwire. ACS NANO 2012; 6:4369-4374. [PMID: 22482745 DOI: 10.1021/nn3010558] [Citation(s) in RCA: 73] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
We demonstrated a flexible strain sensor based on ZnSnO(3) nanowires/microwires for the first time. High-resolution transmission electron microscopy indicates that the ZnSnO(3) belongs to a rhombohedral structure with an R3c space group and is grown along the [001] axis. On the basis of our experimental observation and theoretical calculation, the characteristic I-V curves of ZnSnO(3) revealed that our strain sensors had ultrahigh sensitivity, which is attributed to the piezopotential-modulated change in Schottky barrier height (SBH), that is, the piezotronic effect. The on/off ratio of our device is ∼587, and a gauge factor of 3740 has been demonstrated, which is 19 times higher than that of Si and three times higher than those of carbon nanotubes and ZnO nanowires.
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Affiliation(s)
- Jyh Ming Wu
- School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, USA
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291
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Liu YY, Vasudevan RK, Pan K, Xie SH, Liang WI, Kumar A, Jesse S, Chen YC, Chu YH, Nagarajan V, Kalinin SV, Li JY. Controlling magnetoelectric coupling by nanoscale phase transformation in strain engineered bismuth ferrite. NANOSCALE 2012; 4:3175-3183. [PMID: 22517294 DOI: 10.1039/c2nr00039c] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
The magnetoelectric coupling in multiferroic materials is promising for a wide range of applications, yet manipulating magnetic ordering by electric field proves elusive to obtain and difficult to control. In this paper, we explore the prospect of controlling magnetic ordering in misfit strained bismuth ferrite (BiFeO(3), BFO) films, combining theoretical analysis, numerical simulations, and experimental characterizations. Electric field induced transformation from a tetragonal phase to a distorted rhombohedral one in strain engineered BFO films has been identified by thermodynamic analysis, and realized by scanning probe microscopy (SPM) experiment. By breaking the rotational symmetry of a tip-induced electric field as suggested by phase field simulation, the morphology of distorted rhombohedral variants has been delicately controlled and regulated. Such capabilities enable nanoscale control of magnetoelectric coupling in strain engineered BFO films that is difficult to achieve otherwise, as demonstrated by phase field simulations.
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Affiliation(s)
- Y Y Liu
- Faculty of Materials, Optoelectronics and Physics, and Key Laboratory of Low Dimensional Materials & Application Technology of Ministry of Education, Xiangtan University, Xiangtan, Hunan 411105, China
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292
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Griggio F, Jesse S, Kumar A, Ovchinnikov O, Kim H, Jackson TN, Damjanovic D, Kalinin SV, Trolier-McKinstry S. Substrate clamping effects on irreversible domain wall dynamics in lead zirconate titanate thin films. PHYSICAL REVIEW LETTERS 2012; 108:157604. [PMID: 22587285 DOI: 10.1103/physrevlett.108.157604] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2011] [Revised: 02/14/2012] [Indexed: 05/31/2023]
Abstract
The role of long-range strain interactions on domain wall dynamics is explored through macroscopic and local measurements of nonlinear behavior in mechanically clamped and released polycrystalline lead zirconate-titanate (PZT) films. Released films show a dramatic change in the global dielectric nonlinearity and its frequency dependence as a function of mechanical clamping. Furthermore, we observe a transition from strong clustering of the nonlinear response for the clamped case to almost uniform nonlinearity for the released film. This behavior is ascribed to increased mobility of domain walls. These results suggest the dominant role of collective strain interactions mediated by the local and global mechanical boundary conditions on the domain wall dynamics. The work presented in this Letter demonstrates that measurements on clamped films may considerably underestimate the piezoelectric coefficients and coupling constants of released structures used in microelectromechanical systems, energy harvesting systems, and microrobots.
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Affiliation(s)
- F Griggio
- Materials Research Institute and Materials Science and Engineering Department, The Pennsylvania State University, University Park, Pennsylvania 16802, USA
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293
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Caviglia AD, Scherwitzl R, Popovich P, Hu W, Bromberger H, Singla R, Mitrano M, Hoffmann MC, Kaiser S, Zubko P, Gariglio S, Triscone JM, Först M, Cavalleri A. Ultrafast strain engineering in complex oxide heterostructures. PHYSICAL REVIEW LETTERS 2012; 108:136801. [PMID: 22540718 DOI: 10.1103/physrevlett.108.136801] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/04/2011] [Indexed: 05/23/2023]
Abstract
We report on ultrafast optical experiments in which femtosecond midinfrared radiation is used to excite the lattice of complex oxide heterostructures. By tuning the excitation energy to a vibrational mode of the substrate, a long-lived five-order-of-magnitude increase of the electrical conductivity of NdNiO(3) epitaxial thin films is observed as a structural distortion propagates across the interface. Vibrational excitation, extended here to a wide class of heterostructures and interfaces, may be conducive to new strategies for electronic phase control at THz repetition rates.
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Affiliation(s)
- A D Caviglia
- Max-Planck Research Group for Structural Dynamics-Center for Free Electron Laser Science, University of Hamburg, Notkestrasse 85, 22607 Hamburg, Germany.
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294
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Kreisel J, Alexe M, Thomas PA. A photoferroelectric material is more than the sum of its parts. NATURE MATERIALS 2012; 11:260. [PMID: 22437772 DOI: 10.1038/nmat3282] [Citation(s) in RCA: 89] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
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295
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Sardar K, Hong J, Catalan G, Biswas PK, Lees MR, Walton RI, Scott JF, Redfern SAT. Structural, spectroscopic, magnetic and electrical characterization of Ca-doped polycrystalline bismuth ferrite, Bi(1-x)Ca(x)FeO(3-x/2) (x ≤ 0.1). JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2012; 24:045905. [PMID: 22214552 DOI: 10.1088/0953-8984/24/4/045905] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
The crystal structure and physical properties of multiferroic polycrystalline Ca(2+)-doped BiFeO(3) samples have been investigated. The present experimental investigation suggests that Bi(1-x)Ca(x)FeO(3-x/2) (x ≤ 0.1) can be considered as a solid solution between BiFeO(3) and CaFeO(2.5). The oxidation state of Fe in these materials is + 3 and charge balance occurs through the creation of oxygen vacancies. For each composition, two structural phase transitions are revealed as anomalies in the variable-temperature in situ x-ray diffraction data which is consistent with the well-established high-temperature structural transformation in pure BiFeO(3). All compositions studied show antiferromagnetic behaviour along with a ferromagnetic component that increases with Ca(2+) doping. The resistivities of the Bi(1-x)Ca(x)FeO(3-x/2) samples at room temperature are of the order of 10(9) Ω cm and decrease with increasing Ca(2+) content. Arrhenius plots of the resistivity show two distinct linear regions with activation energies in the range of 0.4-0.7 and 0.03-0.16 eV. A correlation has been established between the critical temperatures associated with the structural phase transitions and the multiferroic properties. A composition of x = 0.085 is predicted to show maximum magneto-electric coupling.
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296
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Rossell MD, Erni R, Prange MP, Idrobo JC, Luo W, Zeches RJ, Pantelides ST, Ramesh R. Atomic structure of highly strained BiFeO3 thin films. PHYSICAL REVIEW LETTERS 2012; 108:047601. [PMID: 22400888 DOI: 10.1103/physrevlett.108.047601] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/11/2011] [Indexed: 05/31/2023]
Abstract
We determine the atomic structure of the pseudotetragonal T phase and the pseudorhombohedral R phase in highly strained multiferroic BiFeO(3) thin films by using a combination of atomic-resolution scanning transmission electron microscopy and electron energy-loss spectroscopy. The coordination of the Fe atoms and their displacement relative to the O and Bi positions are assessed by direct imaging. These observations allow us to interpret the electronic structure data derived from electron energy-loss spectroscopy and provide evidence for the giant spontaneous polarization in strained BiFeO(3) thin films.
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Affiliation(s)
- M D Rossell
- Electron Microscopy Center, Empa, Swiss Federal Laboratories for Materials Science and Technology, CH-8600 Dübendorf, Switzerland.
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297
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Infante IC, Juraszek J, Fusil S, Dupé B, Gemeiner P, Diéguez O, Pailloux F, Jouen S, Jacquet E, Geneste G, Pacaud J, Íñiguez J, Bellaiche L, Barthélémy A, Dkhil B, Bibes M. Multiferroic phase transition near room temperature in BiFeO3 films. PHYSICAL REVIEW LETTERS 2011; 107:237601. [PMID: 22182123 DOI: 10.1103/physrevlett.107.237601] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2011] [Indexed: 05/31/2023]
Abstract
In multiferroic BiFeO(3) thin films grown on highly mismatched LaAlO(3) substrates, we reveal the coexistence of two differently distorted polymorphs that leads to striking features in the temperature dependence of the structural and multiferroic properties. Notably, the highly distorted phase quasiconcomitantly presents an abrupt structural change, transforms from a standard to a nonconventional ferroelectric, and transitions from antiferromagnetic to paramagnetic at 360±20 K. These coupled ferroic transitions just above room temperature hold promises of giant piezoelectric, magnetoelectric, and piezomagnetic responses, with potential in many applications fields.
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Affiliation(s)
- I C Infante
- Unité Mixte de Physique CNRS/Thales, Campus de l'Ecole Polytechnique, 1 avenue Fresnel, 91767 Palaiseau, France
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298
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Ko KT, Jung MH, He Q, Lee JH, Woo CS, Chu K, Seidel J, Jeon BG, Oh YS, Kim KH, Liang WI, Chen HJ, Chu YH, Jeong YH, Ramesh R, Park JH, Yang CH. Concurrent transition of ferroelectric and magnetic ordering near room temperature. Nat Commun 2011; 2:567. [DOI: 10.1038/ncomms1576] [Citation(s) in RCA: 124] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2011] [Accepted: 10/28/2011] [Indexed: 11/09/2022] Open
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299
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Manbachi A, Cobbold RSC. Development and Application of Piezoelectric Materials for Ultrasound Generation and Detection. ULTRASOUND : JOURNAL OF THE BRITISH MEDICAL ULTRASOUND SOCIETY 2011. [DOI: 10.1258/ult.2011.011027] [Citation(s) in RCA: 114] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The piezoelectric effect and its converse are the primary means used in biomedical ultrasound for converting acoustical energy into electrical energy and vice versa. Piezoelectricity has found many bioengineering applications ranging from ultrasound imaging and therapeutics, to piezoelectric surgery and microelectromechanical systems, and to biomedical implants with associated energy harvesting. Because of its fundamental importance to the proper functioning of most medical ultrasound systems, it is important to gain a general understanding of the effect, the history of its development and from this, an appreciation of its limitations and advantages in the generation and detection of ultrasound. This article describes the historical evolvement associated with its use in relation to most medical ultrasound applications and is intended to serve as an introduction for non-expert readers.
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Affiliation(s)
- Amir Manbachi
- Institute of Biomaterials and Biomedical Engineering Ultrasound Group, 164 College Street, Toronto, Ontario, Canada M5S 3G9
| | - Richard S C Cobbold
- Institute of Biomaterials and Biomedical Engineering Ultrasound Group, 164 College Street, Toronto, Ontario, Canada M5S 3G9
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300
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Catalan G, Lubk A, Vlooswijk AHG, Snoeck E, Magen C, Janssens A, Rispens G, Rijnders G, Blank DHA, Noheda B. Flexoelectric rotation of polarization in ferroelectric thin films. NATURE MATERIALS 2011; 10:963-967. [PMID: 22001961 DOI: 10.1038/nmat3141] [Citation(s) in RCA: 167] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/12/2011] [Accepted: 09/08/2011] [Indexed: 05/31/2023]
Abstract
Strain engineering enables modification of the properties of thin films using the stress from the substrates on which they are grown. Strain may be relaxed, however, and this can also modify the properties thanks to the coupling between strain gradient and polarization known as flexoelectricity. Here we have studied the strain distribution inside epitaxial films of the archetypal ferroelectric PbTiO(3), where the mismatch with the substrate is relaxed through the formation of domains (twins). Synchrotron X-ray diffraction and high-resolution scanning transmission electron microscopy reveal an intricate strain distribution, with gradients in both the vertical and, unexpectedly, the horizontal direction. These gradients generate a horizontal flexoelectricity that forces the spontaneous polarization to rotate away from the normal. Polar rotations are a characteristic of compositionally engineered morphotropic phase boundary ferroelectrics with high piezoelectricity; flexoelectricity provides an alternative route for generating such rotations in standard ferroelectrics using purely physical means.
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Affiliation(s)
- G Catalan
- Zernike Institute for Advanced Materials, University of Groningen, 9747 AG Groningen, The Netherlands.
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