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Aramberri H, Íñiguez-González J. Brownian Electric Bubble Quasiparticles. PHYSICAL REVIEW LETTERS 2024; 132:136801. [PMID: 38613274 DOI: 10.1103/physrevlett.132.136801] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/19/2023] [Accepted: 02/27/2024] [Indexed: 04/14/2024]
Abstract
Recent works on electric bubbles (including the experimental demonstration of electric skyrmions) constitute a breakthrough akin to the discovery of magnetic skyrmions some 15 years ago. So far research has focused on obtaining and visualizing these objects, which often appear to be immobile (pinned) in experiments. Thus, critical aspects of magnetic skyrmions-e.g., their quasiparticle nature, Brownian motion-remain unexplored (unproven) for electric bubbles. Here we use predictive atomistic simulations to investigate the basic dynamical properties of these objects in pinning-free model systems. We show that it is possible to find regimes where the electric bubbles can present long lifetimes (∼ns) despite being relatively small (diameter <2 nm). Additionally, we find that they can display stochastic dynamics with large and highly tunable diffusion constants. We thus establish the quasiparticle nature of electric bubbles and put them forward for the physical effects and applications (e.g., in token-based probabilistic computing) considered for magnetic skyrmions.
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Affiliation(s)
- Hugo Aramberri
- Materials Research and Technology Department, Luxembourg Institute of Science and Technology (LIST), Avenue des Hauts-Fourneaux 5, L-4362 Esch/Alzette, Luxembourg
| | - Jorge Íñiguez-González
- Materials Research and Technology Department, Luxembourg Institute of Science and Technology (LIST), Avenue des Hauts-Fourneaux 5, L-4362 Esch/Alzette, Luxembourg
- Department of Physics and Materials Science, University of Luxembourg, Rue du Brill 41, L-4422 Belvaux, Luxembourg
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2
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Lupi E, Wexler RB, Meyers D, Zahradnik A, Jiang Y, Susarla S, Ramesh R, Martin LW, Rappe AM. Engineering Relaxor Behavior in (BaTiO 3 ) n /(SrTiO 3 ) n Superlattices. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2023; 35:e2302012. [PMID: 37433562 DOI: 10.1002/adma.202302012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/02/2023] [Revised: 07/02/2023] [Accepted: 07/10/2023] [Indexed: 07/13/2023]
Abstract
Complex-oxide superlattices provide a pathway to numerous emergent phenomena because of the juxtaposition of disparate properties and the strong interfacial interactions in these unit-cell-precise structures. This is particularly true in superlattices of ferroelectric and dielectric materials, wherein new forms of ferroelectricity, exotic dipolar textures, and distinctive domain structures can be produced. Here, relaxor-like behavior, typically associated with the chemical inhomogeneity and complexity of solid solutions, is observed in (BaTiO3 )n /(SrTiO3 )n (n = 4-20 unit cells) superlattices. Dielectric studies and subsequent Vogel-Fulcher analysis show significant frequency dispersion of the dielectric maximum across a range of periodicities, with enhanced dielectric constant and more robust relaxor behavior for smaller period n. Bond-valence molecular-dynamics simulations predict the relaxor-like behavior observed experimentally, and interpretations of the polar patterns via 2D discrete-wavelet transforms in shorter-period superlattices suggest that the relaxor behavior arises from shape variations of the dipolar configurations, in contrast to frozen antipolar stripe domains in longer-period superlattices (n = 16). Moreover, the size and shape of the dipolar configurations are tuned by superlattice periodicity, thus providing a definitive design strategy to use superlattice layering to create relaxor-like behavior which may expand the ability to control desired properties in these complex systems.
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Affiliation(s)
- Eduardo Lupi
- Department of Materials Science and Engineering, University of California, Berkeley, Berkeley, CA, 94720, USA
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Robert B Wexler
- Department of Chemistry, University of Pennsylvania, Philadelphia, PA, 19104-6323, USA
- Department of Chemistry, Washington University in St. Louis, St. Louis, MO, 63130, USA
| | - Derek Meyers
- Department of Materials Science and Engineering, University of California, Berkeley, Berkeley, CA, 94720, USA
- Department of Physics, Oklahoma State University, Stillwater, OK, 74078, USA
| | - Anton Zahradnik
- Department of Materials Science and Engineering, University of California, Berkeley, Berkeley, CA, 94720, USA
| | - Yizhe Jiang
- Department of Materials Science and Engineering, University of California, Berkeley, Berkeley, CA, 94720, USA
| | - Sandhya Susarla
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Ramamoorthy Ramesh
- Department of Materials Science and Engineering, University of California, Berkeley, Berkeley, CA, 94720, USA
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Lane W Martin
- Department of Materials Science and Engineering, University of California, Berkeley, Berkeley, CA, 94720, USA
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Andrew M Rappe
- Department of Chemistry, University of Pennsylvania, Philadelphia, PA, 19104-6323, USA
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3
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Wen H, Zhang H, Peng R, Liu C, Liu S, Liu F, Xie H, Liu Z. 3D Strain Measurement of Heterostructures Using the Scanning Transmission Electron Microscopy Moiré Depth Sectioning Method. SMALL METHODS 2023; 7:e2300107. [PMID: 37300326 DOI: 10.1002/smtd.202300107] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/28/2023] [Revised: 05/03/2023] [Indexed: 06/12/2023]
Abstract
The mechanical properties of micro- and nanoscale materials directly determine the reliability of heterostructures, microstructures, and microdevices. Therefore, an accurate evaluation of the 3D strain field at the nanoscale is important. In this study, a scanning transmission electron microscopy (STEM) moiré depth sectioning method is proposed. By optimizing the scanning parameters of electron probes at different depths of the material, the sequence STEM moiré fringes (STEM-MFs) with a large field of view, which can be hundreds of nanometers obtained. Then, the 3D STEM moiré information constructed. To some extent, multi-scale 3D strain field measurements from nanometer to the submicrometer scale actualized. The 3D strain field near the heterostructure interface and single dislocation accurately measured by the developed method.
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Affiliation(s)
- Huihui Wen
- School of Electrical Engineering, Hebei University of Science and Technology, Shijiazhuang, 050018, China
- School of Aerospace Engineering, Beijing Institute of Technology, Beijing, 100081, China
| | - Hongye Zhang
- School of Aerospace Engineering, Beijing Institute of Technology, Beijing, 100081, China
- School of Technology, Beijing Forestry University, Beijing, 100083, China
| | - Runlai Peng
- School of Technology, Beijing Forestry University, Beijing, 100083, China
| | - Chao Liu
- Key Laboratory of Semiconductor Materials Science, Institute of Semiconductors, Chinese Academy of Sciences, Beijing, 100083, China
| | - Shuman Liu
- Key Laboratory of Semiconductor Materials Science, Institute of Semiconductors, Chinese Academy of Sciences, Beijing, 100083, China
| | - Fengqi Liu
- Key Laboratory of Semiconductor Materials Science, Institute of Semiconductors, Chinese Academy of Sciences, Beijing, 100083, China
| | - Huimin Xie
- AML, Department of Engineering Mechanics, Tsinghua University, Beijing, 100084, China
| | - Zhanwei Liu
- School of Aerospace Engineering, Beijing Institute of Technology, Beijing, 100081, China
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4
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Graf M, Aramberri H, Zubko P, Íñiguez J. Giant voltage amplification from electrostatically induced incipient ferroelectric states. NATURE MATERIALS 2022; 21:1252-1257. [PMID: 36008605 PMCID: PMC9622417 DOI: 10.1038/s41563-022-01332-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/25/2022] [Accepted: 07/12/2022] [Indexed: 06/15/2023]
Abstract
Ferroelectrics subject to suitable electric boundary conditions present a steady negative capacitance response1,2. When the ferroelectric is in a heterostructure, this behaviour yields a voltage amplification in the other elements, which experience a potential difference larger than the one applied, holding promise for low-power electronics3. So far research has focused on verifying this effect and little is known about how to optimize it. Here, we describe an electrostatic theory of ferroelectric/dielectric superlattices, convenient model systems4,5, and show the relationship between the negative permittivity of the ferroelectric layers and the voltage amplification in the dielectric ones. Then, we run simulations of PbTiO3/SrTiO3 superlattices to reveal the factors most strongly affecting the amplification. In particular, we find that giant effects (up to tenfold increases) can be obtained when PbTiO3 is brought close to the so-called 'incipient ferroelectric' state.
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Affiliation(s)
- Mónica Graf
- Materials Research and Technology Department, Luxembourg Institute of Science and Technology (LIST), Esch/Alzette, Luxembourg
| | - Hugo Aramberri
- Materials Research and Technology Department, Luxembourg Institute of Science and Technology (LIST), Esch/Alzette, Luxembourg
| | - Pavlo Zubko
- London Centre for Nanotechnology and Department of Physics and Astronomy, University College London, London, UK
| | - Jorge Íñiguez
- Materials Research and Technology Department, Luxembourg Institute of Science and Technology (LIST), Esch/Alzette, Luxembourg.
- Department of Physics and Materials Science, University of Luxembourg, Belvaux, Luxembourg.
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5
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Aramberri H, Fedorova NS, Íñiguez J. Ferroelectric/paraelectric superlattices for energy storage. SCIENCE ADVANCES 2022; 8:eabn4880. [PMID: 35921413 PMCID: PMC9348786 DOI: 10.1126/sciadv.abn4880] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Accepted: 06/16/2022] [Indexed: 06/09/2023]
Abstract
The polarization response of antiferroelectrics to electric fields is such that the materials can store large energy densities, which makes them promising candidates for energy storage applications in pulsed-power technologies. However, relatively few materials of this kind are known. Here, we consider ferroelectric/paraelectric superlattices as artificial electrostatically engineered antiferroelectrics. Specifically, using high-throughput second-principles calculations, we engineer PbTiO3/SrTiO3 superlattices to optimize their energy storage performance at room temperature (to maximize density and release efficiency) with respect to different design variables (layer thicknesses, epitaxial conditions, and stiffness of the dielectric layer). We obtain results competitive with the state-of-the-art antiferroelectric capacitors and reveal the mechanisms responsible for the optimal properties.
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Affiliation(s)
- Hugo Aramberri
- Materials Research and Technology Department, Luxembourg Institute of Science and Technology, 5 Avenue des Hauts-Fourneaux, L-4362 Esch/Alzette, Luxembourg
- Inter-Institutional Research Group Uni.lu-LIST on Ferroic Materials, 41 Rue du Brill, L-4422 Belvaux, Luxembourg
| | - Natalya S. Fedorova
- Materials Research and Technology Department, Luxembourg Institute of Science and Technology, 5 Avenue des Hauts-Fourneaux, L-4362 Esch/Alzette, Luxembourg
- Inter-Institutional Research Group Uni.lu-LIST on Ferroic Materials, 41 Rue du Brill, L-4422 Belvaux, Luxembourg
| | - Jorge Íñiguez
- Materials Research and Technology Department, Luxembourg Institute of Science and Technology, 5 Avenue des Hauts-Fourneaux, L-4362 Esch/Alzette, Luxembourg
- Inter-Institutional Research Group Uni.lu-LIST on Ferroic Materials, 41 Rue du Brill, L-4422 Belvaux, Luxembourg
- Department of Physics and Materials Science, University of Luxembourg, 41 Rue du Brill, L-4422 Belvaux, Luxembourg
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6
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Denneulin T, Everhardt AS. A transmission electron microscopy study of low-strain epitaxial BaTiO 3grown onto NdScO 3. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2022; 34:235701. [PMID: 35287120 DOI: 10.1088/1361-648x/ac5db3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2022] [Accepted: 03/14/2022] [Indexed: 06/14/2023]
Abstract
Ferroelectric materials exhibit a strong coupling between strain and electrical polarization. In epitaxial thin films, the strain induced by the substrate can be used to tune the domain structure. Substrates of rare-earth scandates are sometimes selected for the growth of ferroelectric oxides because of their close lattice match, which allows the growth of low-strain dislocation-free layers. Transmission electron microscopy (TEM) is a frequently used technique for investigating ferroelectric domains at the nanometer-scale. However, it requires to thin the specimen down to electron transparency, which can modify the strain and the electrostatic boundary conditions. Here, we have investigated a 320 nm thick epitaxial layer of BaTiO3grown onto an orthorhombic substrate of NdScO3with interfacial lattice strains of -0.45% and -0.05% along the two in-plane directions. We show that the domain structure of the layer can be significantly altered by TEM sample preparation depending on the orientation and the geometry of the lamella. In the as-grown state, the sample shows an anisotropica/cferroelastic domain pattern in the direction of largest strain. If a TEM lamella is cut perpendicular to this direction so that strain is released, a new domain pattern is obtained, which consists of bundles of thin horizontal stripes parallel to the interfaces. These stripe domains correspond to a sheared crystalline structure (orthorhombic or monoclinic) with inclined polarization vectors and with at least four variants of polarization. The stripe domains are distributed in triangular-shaped 180° domains where the average polarization is parallel to the growth direction. The influence of external electric fields on this domain structure was investigated usingin situbiasing and dark-field imaging in TEM.
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Affiliation(s)
- T Denneulin
- Ernst Ruska Centre for Microscopy and Spectroscopy with Electrons and Peter Grünberg Institute, Forschungszentrum Jülich, Jülich 52425, Germany
- CEMES, CNRS, 29 Rue Jeanne Marvig, 31055 Toulouse, France
| | - A S Everhardt
- Zernike Institute for Advanced Materials, University of Groningen, 9747 AG Groningen, The Netherlands
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7
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Temperature Dependence of Dielectric Properties of Ferroelectric Heterostructures with Domain-Provided Negative Capacitance. NANOMATERIALS 2021; 12:nano12010075. [PMID: 35010024 PMCID: PMC8747052 DOI: 10.3390/nano12010075] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Revised: 12/09/2021] [Accepted: 12/21/2021] [Indexed: 11/27/2022]
Abstract
It is well known that the ferroelectric layers in dielectric/ferroelectric/dielectric heterostructures harbor polarization domains resulting in the negative capacitance crucial for manufacturing energy-efficient field-effect transistors. However, the temperature behavior of the characteristic dielectric properties, and, hence, the corresponding behavior of the negative capacitance, are still poorly understood, restraining the technological progress thereof. Here we investigate the temperature-dependent properties of domain structures in the SrTiO3/PbTiO3/SrTiO3 heterostructures and demonstrate that the temperature–thickness phase diagram of the system includes the ferroelectric and paraelectric regions, which exhibit different responses to the applied electric field. Using phase-field modeling and analytical calculations we find the temperature dependence of the dielectric constant of ferroelectric layers and identify the regions of the phase diagram wherein the system demonstrates negative capacitance. We further discuss the optimal routes for implementing negative capacitance in energy-efficient ferroelectric field-effect transistors.
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8
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Sarott MF, Gradauskaite E, Nordlander J, Strkalj N, Trassin M. In situmonitoring of epitaxial ferroelectric thin-film growth. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2021; 33:293001. [PMID: 33873174 DOI: 10.1088/1361-648x/abf979] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/23/2019] [Accepted: 04/19/2021] [Indexed: 06/12/2023]
Abstract
In ferroelectric thin films, the polarization state and the domain configuration define the macroscopic ferroelectric properties such as the switching dynamics. Engineering of the ferroelectric domain configuration during synthesis is in permanent evolution and can be achieved by a range of approaches, extending from epitaxial strain tuning over electrostatic environment control to the influence of interface atomic termination. Exotic polar states are now designed in the technologically relevant ultrathin regime. The promise of energy-efficient devices based on ultrathin ferroelectric films depends on the ability to create, probe, and manipulate polar states in ever more complex epitaxial architectures. Because most ferroelectric oxides exhibit ferroelectricity during the epitaxial deposition process, the direct access to the polarization emergence and its evolution during the growth process, beyond the realm of existing structuralin situdiagnostic tools, is becoming of paramount importance. We review the recent progress in the field of monitoring polar states with an emphasis on the non-invasive probes allowing investigations of polarization during the thin film growth of ferroelectric oxides. A particular importance is given to optical second harmonic generationin situ. The ability to determine the net polarization and domain configuration of ultrathin films and multilayers during the growth of multilayers brings new insights towards a better understanding of the physics of ultrathin ferroelectrics and further control of ferroelectric-based heterostructures for devices.
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Affiliation(s)
- Martin F Sarott
- Department of Materials, ETH Zurich, Vladimir-Prelog-Weg 4, 8093 Zurich, Switzerland
| | - Elzbieta Gradauskaite
- Department of Materials, ETH Zurich, Vladimir-Prelog-Weg 4, 8093 Zurich, Switzerland
| | - Johanna Nordlander
- Department of Materials, ETH Zurich, Vladimir-Prelog-Weg 4, 8093 Zurich, Switzerland
| | - Nives Strkalj
- Department of Materials, ETH Zurich, Vladimir-Prelog-Weg 4, 8093 Zurich, Switzerland
| | - Morgan Trassin
- Department of Materials, ETH Zurich, Vladimir-Prelog-Weg 4, 8093 Zurich, Switzerland
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9
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Hadjimichael M, Li Y, Zatterin E, Chahine GA, Conroy M, Moore K, Connell ENO, Ondrejkovic P, Marton P, Hlinka J, Bangert U, Leake S, Zubko P. Metal-ferroelectric supercrystals with periodically curved metallic layers. NATURE MATERIALS 2021; 20:495-502. [PMID: 33398118 DOI: 10.1038/s41563-020-00864-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/09/2019] [Accepted: 10/26/2020] [Indexed: 06/12/2023]
Abstract
Simultaneous manipulation of multiple boundary conditions in nanoscale heterostructures offers a versatile route to stabilizing unusual structures and emergent phases. Here, we show that a stable supercrystal phase comprising a three-dimensional ordering of nanoscale domains with tailored periodicities can be engineered in PbTiO3-SrRuO3 ferroelectric-metal superlattices. A combination of laboratory and synchrotron X-ray diffraction, piezoresponse force microscopy, scanning transmission electron microscopy and phase-field simulations reveals a complex hierarchical domain structure that forms to minimize the elastic and electrostatic energy. Large local deformations of the ferroelectric lattice are accommodated by periodic lattice modulations of the metallic SrRuO3 layers with curvatures up to 107 m-1. Our results show that multidomain ferroelectric systems can be exploited as versatile templates to induce large curvatures in correlated materials, and present a route for engineering correlated materials with modulated structural and electronic properties that can be controlled using electric fields.
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Affiliation(s)
- Marios Hadjimichael
- London Centre for Nanotechnology, London, UK.
- Department of Physics and Astronomy, University College London, London, UK.
- Department of Quantum Matter Physics, University of Geneva, Geneva, Switzerland.
| | - Yaqi Li
- Department of Physics and Astronomy, University College London, London, UK
| | - Edoardo Zatterin
- Department of Physics and Astronomy, University College London, London, UK
- The European Synchrotron Radiation Facility (ESRF), Grenoble, France
| | - Gilbert A Chahine
- Université Grenoble Alpes, CNRS, Grenoble INP, SIMAP, Grenoble, France
| | - Michele Conroy
- Department of Physics, Bernal Institute, University of Limerick, Limerick, Ireland
| | - Kalani Moore
- Department of Physics, Bernal Institute, University of Limerick, Limerick, Ireland
| | - Eoghan N O' Connell
- Department of Physics, Bernal Institute, University of Limerick, Limerick, Ireland
| | - Petr Ondrejkovic
- Institute of Physics of the Czech Academy of Sciences, Praha, Czech Republic
| | - Pavel Marton
- Institute of Physics of the Czech Academy of Sciences, Praha, Czech Republic
| | - Jiri Hlinka
- Institute of Physics of the Czech Academy of Sciences, Praha, Czech Republic
| | - Ursel Bangert
- Department of Physics, Bernal Institute, University of Limerick, Limerick, Ireland
| | - Steven Leake
- The European Synchrotron Radiation Facility (ESRF), Grenoble, France
| | - Pavlo Zubko
- London Centre for Nanotechnology, London, UK.
- Department of Physics and Astronomy, University College London, London, UK.
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10
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Das S, Hong Z, Stoica VA, Gonçalves MAP, Shao YT, Parsonnet E, Marksz EJ, Saremi S, McCarter MR, Reynoso A, Long CJ, Hagerstrom AM, Meyers D, Ravi V, Prasad B, Zhou H, Zhang Z, Wen H, Gómez-Ortiz F, García-Fernández P, Bokor J, Íñiguez J, Freeland JW, Orloff ND, Junquera J, Chen LQ, Salahuddin S, Muller DA, Martin LW, Ramesh R. Local negative permittivity and topological phase transition in polar skyrmions. NATURE MATERIALS 2021; 20:194-201. [PMID: 33046856 DOI: 10.1038/s41563-020-00818-y] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2019] [Accepted: 09/01/2020] [Indexed: 06/11/2023]
Abstract
Topological solitons such as magnetic skyrmions have drawn attention as stable quasi-particle-like objects. The recent discovery of polar vortices and skyrmions in ferroelectric oxide superlattices has opened up new vistas to explore topology, emergent phenomena and approaches for manipulating such features with electric fields. Using macroscopic dielectric measurements, coupled with direct scanning convergent beam electron diffraction imaging on the atomic scale, theoretical phase-field simulations and second-principles calculations, we demonstrate that polar skyrmions in (PbTiO3)n/(SrTiO3)n superlattices are distinguished by a sheath of negative permittivity at the periphery of each skyrmion. This enhances the effective dielectric permittivity compared with the individual SrTiO3 and PbTiO3 layers. Moreover, the response of these topologically protected structures to electric field and temperature shows a reversible phase transition from the skyrmion state to a trivial uniform ferroelectric state, accompanied by large tunability of the dielectric permittivity. Pulsed switching measurements show a time-dependent evolution and recovery of the skyrmion state (and macroscopic dielectric response). The interrelationship between topological and dielectric properties presents an opportunity to simultaneously manipulate both by a single, and easily controlled, stimulus, the applied electric field.
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Affiliation(s)
- S Das
- Department of Materials Science and Engineering, University of California, Berkeley, CA, USA.
- Department of Physics, University of California, Berkeley, CA, USA.
| | - Z Hong
- Department of Materials Science and Engineering, The Pennsylvania State University, University Park, PA, USA
- Department of Mechanical Engineering, Carnegie Mellon University, Pittsburgh, PA, USA
| | - V A Stoica
- Department of Materials Science and Engineering, The Pennsylvania State University, University Park, PA, USA
| | - M A P Gonçalves
- Materials Research and Technology Department, Luxembourg Institute of Science and Technology (LIST), Esch/Alzette, Luxemburg
- Departamento de Ciencias de la Tierra y Física de la Materia Condensada, Universidad de Cantabria, Cantabria Campus Internacional, Santander, Spain
- Physics and Materials Science Research Unit, University of Luxembourg, Belvaux, Luxembourg
| | - Y T Shao
- School of Applied and Engineering Physics, Cornell University, Ithaca, NY, USA
| | - E Parsonnet
- Department of Physics, University of California, Berkeley, CA, USA
| | - E J Marksz
- National Institute of Standards and Technology, Boulder, CO, USA
| | - S Saremi
- Department of Materials Science and Engineering, University of California, Berkeley, CA, USA
| | - M R McCarter
- Department of Physics, University of California, Berkeley, CA, USA
| | - A Reynoso
- Department of Physics, University of California, Berkeley, CA, USA
| | - C J Long
- National Institute of Standards and Technology, Boulder, CO, USA
| | - A M Hagerstrom
- National Institute of Standards and Technology, Boulder, CO, USA
| | - D Meyers
- Department of Materials Science and Engineering, University of California, Berkeley, CA, USA
| | - V Ravi
- Department of Materials Science and Engineering, University of California, Berkeley, CA, USA
| | - B Prasad
- Department of Materials Science and Engineering, University of California, Berkeley, CA, USA
| | - H Zhou
- Advanced Photon Source, Argonne National Laboratory, Argonne, IL, USA
| | - Z Zhang
- Advanced Photon Source, Argonne National Laboratory, Argonne, IL, USA
| | - H Wen
- Advanced Photon Source, Argonne National Laboratory, Argonne, IL, USA
| | - F Gómez-Ortiz
- Departamento de Ciencias de la Tierra y Física de la Materia Condensada, Universidad de Cantabria, Cantabria Campus Internacional, Santander, Spain
| | - P García-Fernández
- Departamento de Ciencias de la Tierra y Física de la Materia Condensada, Universidad de Cantabria, Cantabria Campus Internacional, Santander, Spain
| | - J Bokor
- Department of Electrical Engineering and Computer Sciences, University of California, Berkeley, CA, USA
| | - J Íñiguez
- Materials Research and Technology Department, Luxembourg Institute of Science and Technology (LIST), Esch/Alzette, Luxemburg
- Physics and Materials Science Research Unit, University of Luxembourg, Belvaux, Luxembourg
| | - J W Freeland
- Advanced Photon Source, Argonne National Laboratory, Argonne, IL, USA
| | - N D Orloff
- National Institute of Standards and Technology, Boulder, CO, USA
| | - J Junquera
- Departamento de Ciencias de la Tierra y Física de la Materia Condensada, Universidad de Cantabria, Cantabria Campus Internacional, Santander, Spain
| | - L Q Chen
- Department of Materials Science and Engineering, The Pennsylvania State University, University Park, PA, USA
| | - S Salahuddin
- Department of Electrical Engineering and Computer Sciences, University of California, Berkeley, CA, USA
| | - D A Muller
- School of Applied and Engineering Physics, Cornell University, Ithaca, NY, USA
- Kavli Institute at Cornell for Nanoscale Science, Ithaca, NY, USA
| | - L W Martin
- Department of Materials Science and Engineering, University of California, Berkeley, CA, USA
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - R Ramesh
- Department of Materials Science and Engineering, University of California, Berkeley, CA, USA.
- Department of Physics, University of California, Berkeley, CA, USA.
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA.
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11
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Lum CY, Lim KG, Chew KH. Rich antiferroelectric phase diagram of antiferroelectric-ferroelectric superlattices: internal electric field- and interface induced phase transitions. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2020; 32:425401. [PMID: 32544898 DOI: 10.1088/1361-648x/ab9d4a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2020] [Accepted: 06/16/2020] [Indexed: 06/11/2023]
Abstract
We propose a thermodynamic model to the study the antiferroelectric (AFE) phase transitions in antiferroelectric-ferroelectric (AFE-FE) superlattices in which the coupling at the interface between two layers is mediated by local polarizations. Phase diagram of the AFE layer in term of the degree of interfacial effectλand temperatureTinvolving ferrielectric (FI) and ferroelectric (FE) phases is investigated. These two phases are stabilized by the interfacial effect and internal electric field. AFE thicknessLAFEversusTphase diagram is also constructed. Intermediate regions of two-phase coexistence (IM) emerge in theλ-TandLAFE-Tphase diagrams, if certain interface propertiesλand layer thicknessLAFEcriteria are met. These IM regions are metastable states, which exist as a transition state between two phases. A tricritical point locates at the boundaries across the FI, IM and FE phases is found in theLAFE-Tphase diagram. Competition among the internal electric field due to the electrostatic coupling, the FE ordering arises from the interfacial effect and the antiferroelectric ordering within the AFE layer giving rises to the rich AFE phase diagram.
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Affiliation(s)
- C Y Lum
- Center for Theoretical and Computational Physics, Department of Physics, University of Malaya, 50603 Kuala Lumpur, Malaysia
- Department of Foundation Studies, RCSI UCD Malaysia Campus, 10450 Penang, Malaysia
| | - K-G Lim
- University of Southampton Malaysia, 79200 Iskandar Puteri, Johor, Malaysia
| | - K-H Chew
- Center for Theoretical and Computational Physics, Department of Physics, University of Malaya, 50603 Kuala Lumpur, Malaysia
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12
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Tikhonov Y, Kondovych S, Mangeri J, Pavlenko M, Baudry L, Sené A, Galda A, Nakhmanson S, Heinonen O, Razumnaya A, Luk'yanchuk I, Vinokur VM. Controllable skyrmion chirality in ferroelectrics. Sci Rep 2020; 10:8657. [PMID: 32457537 PMCID: PMC7251125 DOI: 10.1038/s41598-020-65291-8] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2020] [Accepted: 04/30/2020] [Indexed: 11/13/2022] Open
Abstract
Chirality, an intrinsic handedness, is one of the most intriguing fundamental phenomena in nature. Materials composed of chiral molecules find broad applications in areas ranging from nonlinear optics and spintronics to biology and pharmaceuticals. However, chirality is usually an invariable inherent property of a given material that cannot be easily changed at will. Here, we demonstrate that ferroelectric nanodots support skyrmions the chirality of which can be controlled and switched. We devise protocols for realizing control and efficient manipulations of the different types of skyrmions. Our findings open the route for controlled chirality with potential applications in ferroelectric-based information technologies.
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Affiliation(s)
- Yu Tikhonov
- Faculty of Physics, Southern Federal University, 5 Zorge str., 344090, Rostov-on-Don, Russia
- University of Picardie, Laboratory of Condensed Matter Physics, Amiens, 80039, France
| | - S Kondovych
- University of Picardie, Laboratory of Condensed Matter Physics, Amiens, 80039, France
- Life Chemicals Inc., Murmanska st. 5, Kyiv, 02660, Ukraine
| | - J Mangeri
- Institute of Physics, Academy of Sciences of the Czech Republic, Na Slovance 2, 18221, Praha 8, Czech Republic
- Department of Physics, University of Connecticut, Storrs, CT, USA
| | - M Pavlenko
- Faculty of Physics, Southern Federal University, 5 Zorge str., 344090, Rostov-on-Don, Russia
| | - L Baudry
- Institute of Electronics, Microelectronics and Nanotechnology (IEMN)-DHS Départment, UMR CNRS 8520, Université des Sciences et Technologies de Lille, 59652, Villeneuve d'Ascq Cedex, France
| | - A Sené
- University of Picardie, Laboratory of Condensed Matter Physics, Amiens, 80039, France
| | - A Galda
- James Franck Institute, University of Chicago, Chicago, Illinois, 60637, USA
| | - S Nakhmanson
- Department of Physics, University of Connecticut, Storrs, CT, USA
- Department of Materials Science & Engineering and Institute of Material Science, University of Connecticut, Storrs, Connecticut, 06269, USA
| | - O Heinonen
- Materials Science Division, Argonne National Laboratory, 9700S. Cass Avenue, Argonne, Illinois, 60637, USA
| | - A Razumnaya
- Faculty of Physics, Southern Federal University, 5 Zorge str., 344090, Rostov-on-Don, Russia
| | - I Luk'yanchuk
- University of Picardie, Laboratory of Condensed Matter Physics, Amiens, 80039, France
- L. D. Landau Institute for Theoretical Physics, Akademika Semenova av., 1A9, Chernogolovka, 142432, Russia
| | - V M Vinokur
- Materials Science Division, Argonne National Laboratory, 9700S. Cass Avenue, Argonne, Illinois, 60637, USA.
- Consortium for Advanced Science and Engineering (CASE) University of Chicago, 5801S Ellis Ave, Chicago, IL, 60637, USA.
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13
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Abstract
Paradigmatic knotted solitons, Hopfions, that are characterized by topological Hopf invariant, attract an intense attention in the diverse areas of physics ranging from high-energy physics, cosmology and astrophysics to biology, magneto- and hydrodynamics and condensed matter physics. Yet, while being of broad interest, they remain elusive and under-explored. Here we demonstrate that Hopfions emerge as a basic configuration of polarization field in confined ferroelectric nanoparticles. Our findings establish that Hopfions are of fundamental importance for the electromagnetic behavior of the nanocomposits and can result in advanced functionalities of these materials. In spite of the growing recognition of the role of Hopfions in topological phases, their physical properties remain poorly understood. Here, the authors theoretically demonstrate that Hopfions are fundamental topological formations in confined ferroelectrics governing their electromagnetic response.
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14
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Repolarization of Ferroelectric Superlattices BaZrO 3/BaTiO 3. Sci Rep 2019; 9:18948. [PMID: 31831812 PMCID: PMC6908576 DOI: 10.1038/s41598-019-55475-2] [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: 01/18/2019] [Accepted: 11/26/2019] [Indexed: 11/09/2022] Open
Abstract
With the use of the modified Sawyer-Tower scheme and Merz technique, studies were conducted on the repolarization characteristics of ferroelectric (BaZrO3/BaTiO3) superlattices on monocrystalline MgO substrate. Studies of temperature changes in the dielectric hysteresis loops indicated a sufficiently smooth decrease in spontaneous polarization compared with homogeneous barium titanate near the phase transition temperature of the superlattice. Experimental studies of switched currents have shown that the switching processes in the synthesized superlattices are implemented in two stages: activation motion (“creep” mode) and non-activation motion (slip mode). The presence of the activation switching stage and the numerical estimates show that with high probability, the movement of domain boundaries accomplishes the processes of switching in the studied superlattice. The threshold field separating the stated stages decreases with increasing temperature up to the Curie point of the superlattice, similar to the coercive field. Detection of the non-strictly exponential dependence of the switching current on the reverse field strength in the activation stage was modulated by the dependence with the power-law exponent for the applied electric field. Both techniques indicate that the studied superlattices have a small internal displacement field directed from the superlattice to the substrate.
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15
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Lee HJ, Shimizu T, Funakubo H, Imai Y, Sakata O, Hwang SH, Kim TY, Yoon C, Dai C, Chen LQ, Lee SY, Jo JY. Electric-Field-Driven Nanosecond Ferroelastic-Domain Switching Dynamics in Epitaxial Pb(Zr,Ti)O_{3} Film. PHYSICAL REVIEW LETTERS 2019; 123:217601. [PMID: 31809179 DOI: 10.1103/physrevlett.123.217601] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2019] [Revised: 08/22/2019] [Indexed: 06/10/2023]
Abstract
Epitaxial oxide ferroelectric films exhibit emerging phenomena arising from complex domain configurations even at pseudoequilibrium, including the creation of domain states unfavored in nature and abrupt piezoelectric coefficients around morphotropic phase boundaries. The nanometer-sized domain configurations and their domain switching dynamics under external stimuli are directly linked to the ultrafast manipulation of ferroelectric thin films; however, complex domain switching dynamics under homogeneous electric fields has not been fully explored, especially at the nanosecond timescale. This Letter reports the nanosecond dynamics of ferroelastic-domain switching from the 90° to 180° direction using time-resolved x-ray microdiffraction under homogeneous electric fields onto an epitaxial Pb(Zr_{0.35},Ti_{0.65})O_{3} film capacitor. It is found that the application of electric fields induces spatially heterogeneous domain switching processes via intermediate domain structures with rotated polarization vectors. In addition, the domain switching time is shown to be inversely proportional to the magnitude of the applied electric field, and electric fields higher than 480 kV/cm are found to complete the ferroelastic switching within nanoseconds.
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Affiliation(s)
- Hyeon Jun Lee
- School of Materials Science and Engineering, Gwangju Institute of Science and Technology, Gwangju 61005, South Korea
| | - Takao Shimizu
- Department of Materials Science and Engineering, School of Materials and Chemical Technology, Tokyo Institute of Technology, Tokyo 152-8550, Japan
| | - Hiroshi Funakubo
- Department of Materials Science and Engineering, School of Materials and Chemical Technology, Tokyo Institute of Technology, Tokyo 152-8550, Japan
| | - Yasuhiko Imai
- SPring-8, Japanese Synchrotron Radiation Research Institute, Hyogo 679-5198, Japan
| | - Osami Sakata
- Synchrotron X-ray Group, Research Center for Advanced Measurement and Characterization, National Institute for Materials Science, Hyogo 679-5148, Japan
| | - Seung Hyun Hwang
- School of Materials Science and Engineering, Gwangju Institute of Science and Technology, Gwangju 61005, South Korea
| | - Tae Yeon Kim
- School of Materials Science and Engineering, Gwangju Institute of Science and Technology, Gwangju 61005, South Korea
| | - Changjae Yoon
- School of Materials Science and Engineering, Gwangju Institute of Science and Technology, Gwangju 61005, South Korea
| | - Cheng Dai
- Department of Materials Science and Engineering, Pennsylvania State University, Pennsylvania 16802, USA
| | - Long Q Chen
- Department of Materials Science and Engineering, Pennsylvania State University, Pennsylvania 16802, USA
| | - Su Yong Lee
- Pohang Accelerator Laboratory, Pohang University of Science and Technology, Pohang 37676, South Korea
| | - Ji Young Jo
- School of Materials Science and Engineering, Gwangju Institute of Science and Technology, Gwangju 61005, South Korea
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16
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Strkalj N, Gradauskaite E, Nordlander J, Trassin M. Design and Manipulation of Ferroic Domains in Complex Oxide Heterostructures. MATERIALS (BASEL, SWITZERLAND) 2019; 12:E3108. [PMID: 31554210 PMCID: PMC6803956 DOI: 10.3390/ma12193108] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/28/2019] [Revised: 09/16/2019] [Accepted: 09/18/2019] [Indexed: 02/06/2023]
Abstract
The current burst of device concepts based on nanoscale domain-control in magnetically and electrically ordered systems motivates us to review the recent development in the design of domain engineered oxide heterostructures. The improved ability to design and control advanced ferroic domain architectures came hand in hand with major advances in investigation capacity of nanoscale ferroic states. The new avenues offered by prototypical multiferroic materials, in which electric and magnetic orders coexist, are expanding beyond the canonical low-energy-consuming electrical control of a net magnetization. Domain pattern inversion, for instance, holds promises of increased functionalities. In this review, we first describe the recent development in the creation of controlled ferroelectric and multiferroic domain architectures in thin films and multilayers. We then present techniques for probing the domain state with a particular focus on non-invasive tools allowing the determination of buried ferroic states. Finally, we discuss the switching events and their domain analysis, providing critical insight into the evolution of device concepts involving multiferroic thin films and heterostructures.
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Affiliation(s)
- Nives Strkalj
- Department of Materials, ETH Zurich, Vladimir-Prelog-Weg 4, 8093 Zurich, Switzerland.
| | - Elzbieta Gradauskaite
- Department of Materials, ETH Zurich, Vladimir-Prelog-Weg 4, 8093 Zurich, Switzerland
| | - Johanna Nordlander
- Department of Materials, ETH Zurich, Vladimir-Prelog-Weg 4, 8093 Zurich, Switzerland
| | - Morgan Trassin
- Department of Materials, ETH Zurich, Vladimir-Prelog-Weg 4, 8093 Zurich, Switzerland.
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17
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Pereira Gonçalves MA, Escorihuela-Sayalero C, Garca-Fernández P, Junquera J, Íñiguez J. Theoretical guidelines to create and tune electric skyrmion bubbles. SCIENCE ADVANCES 2019; 5:eaau7023. [PMID: 30793029 PMCID: PMC6377273 DOI: 10.1126/sciadv.aau7023] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/2018] [Accepted: 12/28/2018] [Indexed: 05/21/2023]
Abstract
Researchers have long wondered whether ferroelectrics may present topological textures akin to magnetic skyrmions and chiral bubbles, the results being modest thus far. An electric equivalent of a typical magnetic skyrmion would rely on a counterpart of the Dzyaloshinskii-Moriya interaction and seems all but impossible; further, the exotic ferroelectric orders reported to date rely on specific composites and superlattices, limiting their generality and properties. Here, we propose an original approach to write topological textures in simple ferroelectrics in a customary manner. Our second-principles simulations of columnar nanodomains, in prototype material PbTiO3, show we can harness the Bloch-type structure of the domain wall to create objects with the usual skyrmion-defining features as well as unusual ones-including isotopological and topological transitions driven by external fields and temperature-and potentially very small sizes. Our results suggest countless possibilities for creating and manipulating such electric textures, effectively inaugurating the field of topological ferroelectrics.
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Affiliation(s)
- M. A. Pereira Gonçalves
- Materials Research and Technology Department, Luxembourg Institute of Science and Technology (LIST), Avenue des Hauts-Fourneaux 5, L-4362 Esch/Alzette, Luxembourg
| | - Carlos Escorihuela-Sayalero
- Materials Research and Technology Department, Luxembourg Institute of Science and Technology (LIST), Avenue des Hauts-Fourneaux 5, L-4362 Esch/Alzette, Luxembourg
| | - Pablo Garca-Fernández
- Departamento de Ciencias de la Tierra y Fsica de la Materia Condensada, Universidad de Cantabria, Cantabria Campus Internacional, Avenida de los Castros s/n, 39005 Santander, Spain
| | - Javier Junquera
- Departamento de Ciencias de la Tierra y Fsica de la Materia Condensada, Universidad de Cantabria, Cantabria Campus Internacional, Avenida de los Castros s/n, 39005 Santander, Spain
| | - Jorge Íñiguez
- Materials Research and Technology Department, Luxembourg Institute of Science and Technology (LIST), Avenue des Hauts-Fourneaux 5, L-4362 Esch/Alzette, Luxembourg
- Physics and Materials Science Research Unit, University of Luxembourg, 41 Rue du Brill, L-4422 Belvaux, Luxembourg
- Corresponding author.
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18
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Park J, Mangeri J, Zhang Q, Yusuf MH, Pateras A, Dawber M, Holt MV, Heinonen OG, Nakhmanson S, Evans PG. Domain alignment within ferroelectric/dielectric PbTiO 3/SrTiO 3 superlattice nanostructures. NANOSCALE 2018; 10:3262-3271. [PMID: 29384166 DOI: 10.1039/c7nr07203a] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The ferroelectric domain pattern within lithographically defined PbTiO3/SrTiO3 ferroelectric/dielectric heteroepitaxial superlattice nanostructures is strongly influenced by the edges of the structures. Synchrotron X-ray nanobeam diffraction reveals that the spontaneously formed 180° ferroelectric stripe domains exhibited by such superlattices adopt a configuration in rectangular nanostructures in which domain walls are aligned with long patterned edges. The angular distribution of X-ray diffuse scattering intensity from nanodomains indicates that domains are aligned within an angular range of approximately 20° with respect to the edges. Computational studies based on a time-dependent Landau-Ginzburg-Devonshire model show that the preferred direction of the alignment results from lowering of the bulk and electrostrictive contributions to the free energy of the system due to the release of the lateral mechanical constraint. This unexpected alignment appears to be intrinsic and not a result of distortions or defects caused by the patterning process. Our work demonstrates how nanostructuring and patterning of heteroepitaxial superlattices allow for pathways to create and control ferroelectric structures that may appear counterintuitive.
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Affiliation(s)
- Joonkyu Park
- Department of Materials Science and Engineering, University of Wisconsin-Madison, Madison, WI 53706, USA.
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19
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Hadjimichael M, Zatterin E, Fernandez-Peña S, Leake SJ, Zubko P. Domain Wall Orientations in Ferroelectric Superlattices Probed with Synchrotron X-Ray Diffraction. PHYSICAL REVIEW LETTERS 2018; 120:037602. [PMID: 29400523 DOI: 10.1103/physrevlett.120.037602] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2017] [Revised: 11/05/2017] [Indexed: 06/07/2023]
Abstract
Ferroelectric domains in PbTiO_{3}/SrTiO_{3} superlattices are studied using synchrotron x-ray diffraction. Macroscopic measurements reveal a change in the preferential domain wall orientation from {100} to {110} crystallographic planes with increasing temperature. The temperature range of this reorientation depends on the ferroelectric layer thickness and domain period. Using a nanofocused beam, local changes in the domain wall orientation within the buried ferroelectric layers are imaged, both in structurally uniform regions of the sample and near defect sites and argon ion-etched patterns. Domain walls are found to exhibit a preferential alignment with the straight edges of the etched patterns as well as with structural features associated with defect sites. The distribution of out-of-plane lattice parameters is mapped around one such feature, showing that it is accompanied by inhomogeneous strain and large strain gradients.
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Affiliation(s)
- Marios Hadjimichael
- London Centre for Nanotechnology and Department of Physics and Astronomy, University College London, 17-19 Gordon Street, WC1H 0AH London, United Kingdom
| | - Edoardo Zatterin
- London Centre for Nanotechnology and Department of Physics and Astronomy, University College London, 17-19 Gordon Street, WC1H 0AH London, United Kingdom
- ESRF-The European Synchrotron, 71 Avenue des Martyrs, 38000 Grenoble, France
| | | | - Steven J Leake
- ESRF-The European Synchrotron, 71 Avenue des Martyrs, 38000 Grenoble, France
| | - Pavlo Zubko
- London Centre for Nanotechnology and Department of Physics and Astronomy, University College London, 17-19 Gordon Street, WC1H 0AH London, United Kingdom
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20
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Ahn Y, Park J, Pateras A, Rich MB, Zhang Q, Chen P, Yusuf MH, Wen H, Dawber M, Evans PG. Photoinduced Domain Pattern Transformation in Ferroelectric-Dielectric Superlattices. PHYSICAL REVIEW LETTERS 2017; 119:057601. [PMID: 28949700 DOI: 10.1103/physrevlett.119.057601] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2017] [Indexed: 06/07/2023]
Abstract
The nanodomain pattern in ferroelectric-dielectric superlattices transforms to a uniform polarization state under above-band-gap optical excitation. X-ray scattering reveals a disappearance of domain diffuse scattering and an expansion of the lattice. The reappearance of the domain pattern occurs over a period of seconds at room temperature, suggesting a transformation mechanism in which charge carriers in long-lived trap states screen the depolarization field. A Landau-Ginzburg-Devonshire model predicts changes in lattice parameter and a critical carrier concentration for the transformation.
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Affiliation(s)
- Youngjun Ahn
- Department of Materials Science and Engineering, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
| | - Joonkyu Park
- Department of Materials Science and Engineering, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
| | - Anastasios Pateras
- Department of Materials Science and Engineering, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
| | - Matthew B Rich
- Department of Materials Science and Engineering, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
| | - Qingteng Zhang
- Department of Materials Science and Engineering, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
| | - Pice Chen
- Department of Materials Science and Engineering, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
| | - Mohammed H Yusuf
- Department of Physics and Astronomy, Stony Brook University, Stony Brook, New York 11794, USA
| | - Haidan Wen
- Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - Matthew Dawber
- Department of Physics and Astronomy, Stony Brook University, Stony Brook, New York 11794, USA
| | - Paul G Evans
- Department of Materials Science and Engineering, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
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21
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Zubko P, Lu H, Bark CW, Martí X, Santiso J, Eom CB, Catalan G, Gruverman A. On the persistence of polar domains in ultrathin ferroelectric capacitors. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2017; 29:284001. [PMID: 28593933 DOI: 10.1088/1361-648x/aa73c3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The instability of ferroelectric ordering in ultra-thin films is one of the most important fundamental issues pertaining realization of a number of electronic devices with enhanced functionality, such as ferroelectric and multiferroic tunnel junctions or ferroelectric field effect transistors. In this paper, we investigate the polarization state of archetypal ultrathin (several nanometres) ferroelectric heterostructures: epitaxial single-crystalline BaTiO3 films sandwiched between the most habitual perovskite electrodes, SrRuO3, on top of the most used perovskite substrate, SrTiO3. We use a combination of piezoresponse force microscopy, dielectric measurements and structural characterization to provide conclusive evidence for the ferroelectric nature of the relaxed polarization state in ultrathin BaTiO3 capacitors. We show that even the high screening efficiency of SrRuO3 electrodes is still insufficient to stabilize polarization in SrRuO3/BaTiO3/SrRuO3 heterostructures at room temperature. We identify the key role of domain wall motion in determining the macroscopic electrical properties of ultrathin capacitors and discuss their dielectric response in the light of the recent interest in negative capacitance behaviour.
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Affiliation(s)
- Pavlo Zubko
- London Centre for Nanotechnology and Department of Physics and Astronomy, University College London, 17-19 Gordon Street, London WC1H 0AH, United Kingdom
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22
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Damodaran AR, Agar JC, Pandya S, Chen Z, Dedon L, Xu R, Apgar B, Saremi S, Martin LW. New modalities of strain-control of ferroelectric thin films. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2016; 28:263001. [PMID: 27187744 DOI: 10.1088/0953-8984/28/26/263001] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Ferroelectrics, with their spontaneous switchable electric polarization and strong coupling between their electrical, mechanical, thermal, and optical responses, provide functionalities crucial for a diverse range of applications. Over the past decade, there has been significant progress in epitaxial strain engineering of oxide ferroelectric thin films to control and enhance the nature of ferroelectric order, alter ferroelectric susceptibilities, and to create new modes of response which can be harnessed for various applications. This review aims to cover some of the most important discoveries in strain engineering over the past decade and highlight some of the new and emerging approaches for strain control of ferroelectrics. We discuss how these new approaches to strain engineering provide promising routes to control and decouple ferroelectric susceptibilities and create new modes of response not possible in the confines of conventional strain engineering. To conclude, we will provide an overview and prospectus of these new and interesting modalities of strain engineering helping to accelerate their widespread development and implementation in future functional devices.
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Affiliation(s)
- Anoop R Damodaran
- Department of Materials Science and Engineering, University of California, Berkeley, Berkeley, California, USA
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23
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Boulle A, Infante IC, Lemée N. Diffuse X-ray scattering from 180° ferroelectric stripe domains: polarization-induced strain, period disorder and wall roughness. J Appl Crystallogr 2016. [DOI: 10.1107/s1600576716005331] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
A key element in ferroic materials is the presence of walls separating domains with different orientations of the order parameter. It is demonstrated that 180° stripe domains in ferroelectric films give rise to very distinct features in their diffuse X-ray scattering (DXS) intensity distributions. A model is developed that allows the determination of not only the domain period but also the period disorder, the thickness and roughness of the domain walls, and the strain induced by the rotation of the polarization. As an example, the model is applied to ferroelectric/paraelectric superlattices. Temperature-dependent DXS measurements reveal that the polarization-induced strain decreases dramatically with increasing temperature and vanishes at the Curie temperature. The motion of ferroelectric domain walls appears to be a collective process that does not create any disorder in the domain period, whereas pinning by structural defects increases the wall roughness. This work will facilitatein situquantitative studies of ferroic domains and domain wall dynamics under the application of external stimuli, including electric fields and temperature.
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24
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Kim GY, Sung KD, Rhyim Y, Yoon SY, Kim MS, Jeong SJ, Kim KH, Ryu J, Kim SD, Choi SY. Enhanced polarization by the coherent heterophase interface between polar and non-polar phases. NANOSCALE 2016; 8:7443-7448. [PMID: 26601654 DOI: 10.1039/c5nr05391a] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
A piezoelectric composite containing the ferroelectric polar (Bi(Na0.8K0.2)0.5TiO3: f-BNKT) and the non-polar (0.94Bi(Na0.75K0.25)0.5TiO3-0.06BiAlO3: BNKT-BA) phases exhibits synergetic properties which combine the beneficial aspects of each phase, i.e., the high saturated polarization (Ps) of the polar phase and the low coercive field (Ec) of the non-polar phase. To understand the origin of such a fruitful outcome from this type of polar/non-polar heterophase structure, comprehensive studies are conducted, including transmission electron microscopy (TEM) and finite element method (FEM) analyses. The TEM results show that the polar/non-polar composite has a core/shell structure in which the polar phase (core) is surrounded by a non-polar phase (shell). In situ electrical biasing TEM experiments visualize that the ferroelectric domains in the polar core are aligned even under an electric field of ∼1 kV mm(-1), which is much lower than its intrinsic coercive field (∼3 kV mm(-1)). From the FEM analyses, we can find that the enhanced polarization of the polar phase is promoted by an additional internal field at the phase boundary which originates from the preferential polarization of the relaxor-like non-polar phase. From the present study, we conclude that the coherent interface between polar and non-polar phases is a key factor for understanding the enhanced piezoelectric properties of the composite.
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Affiliation(s)
- Gi-Yeop Kim
- Materials Modeling & Characterization Department, Korea Institute of Materials Science, Changwon 642-831, South Korea. and School of Materials Science and Engineering, Pusan National University, Pusan 609-735, South Korea
| | - Kil-Dong Sung
- Materials Modeling & Characterization Department, Korea Institute of Materials Science, Changwon 642-831, South Korea.
| | - Youngmok Rhyim
- Materials Modeling & Characterization Department, Korea Institute of Materials Science, Changwon 642-831, South Korea.
| | - Seog-Young Yoon
- School of Materials Science and Engineering, Pusan National University, Pusan 609-735, South Korea
| | - Min-Soo Kim
- Battery Research Center, Korea Electrotechnology Research Institute, Changwon 641-120, South Korea
| | - Soon-Jong Jeong
- Battery Research Center, Korea Electrotechnology Research Institute, Changwon 641-120, South Korea
| | - Kwang-Ho Kim
- School of Materials Science and Engineering, Pusan National University, Pusan 609-735, South Korea
| | - Jungho Ryu
- Functional Ceramics Group, Korea Institute of Materials Science, Changwon 642-831, South Korea
| | - Sung-Dae Kim
- Materials Modeling & Characterization Department, Korea Institute of Materials Science, Changwon 642-831, South Korea.
| | - Si-Young Choi
- Materials Modeling & Characterization Department, Korea Institute of Materials Science, Changwon 642-831, South Korea.
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25
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He B, Wang Z. Enhancement of the Electrical Properties in BaTiO3/PbZr0.52Ti0.48O3 Ferroelectric Superlattices. ACS APPLIED MATERIALS & INTERFACES 2016; 8:6736-6742. [PMID: 26913563 DOI: 10.1021/acsami.5b12098] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
In this study, BaTiO3/Pb(Zr0.52Ti0.48)O3 (BTO/PZT) ferroelectric superlattices have been grown on the Nb-doped SrTiO3 (NSTO) single-crystal substrate by pulsed laser deposition, and their electrical properties were investigated in detail. The leakage current was reduced significantly in the BTO/PZT superlattices, and the conduction mechanism could be interpreted as the bulk-limited mechanism. In addition, a more symmetric hysteresis loop was observed in the BTO/PZT superlattices compared with the pure PZT and BTO films. The BTO/PZT superlattices with the modulation thickness of 9.8 nm showed remarkably improved dielectric properties with dielectric constant and loss of 684 and 0.02, respectively, measured at the frequency of 10 kHz. Based on these experimental results, it can be considered that the BTO/PZT interfaces play a very important role for the enhanced electrical properties of the BTO/PZT superlattices.
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Affiliation(s)
- Bin He
- Shenyang National Laboratory for Materials Science, Institute of Metal Research (IMR), Chinese Academy of Sciences (CAS) , 72 Wenhua Road, Shenyang 110016, China
| | - Zhanjie Wang
- Shenyang National Laboratory for Materials Science, Institute of Metal Research (IMR), Chinese Academy of Sciences (CAS) , 72 Wenhua Road, Shenyang 110016, China
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26
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Kasamatsu S, Watanabe S, Hwang CS, Han S. Emergence of Negative Capacitance in Multidomain Ferroelectric-Paraelectric Nanocapacitors at Finite Bias. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2016; 28:335-340. [PMID: 26568333 DOI: 10.1002/adma.201502916] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/17/2015] [Revised: 10/01/2015] [Indexed: 06/05/2023]
Abstract
The emergence of negative capacitance in an ultrathin ferroelectric/paraelectric bilayer capacitor under electrical bias is examined using first-principles simulation. An antiferroelectric-like behavior is predicted, and negative capacitance is shown to emerge when the monodomain state becomes stable after bias application. The polydomain-monodomain transition is also shown to be a source of capacitance enhancement.
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Affiliation(s)
- Shusuke Kasamatsu
- The Institute for Solid State Physics, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa-shi, Chiba, 277-8581, Japan
| | - Satoshi Watanabe
- Department of Materials Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8656, Japan
| | - Cheol Seong Hwang
- Department of Materials Science and Engineering and Inter-university Semiconductor Research Center, Seoul National University, Seoul, 151-742, South Korea
| | - Seungwu Han
- Department of Materials Science and Engineering, Seoul National University, Seoul, 151-742, South Korea
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27
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Bein B, Hsing HC, Callori SJ, Sinsheimer J, Chinta PV, Headrick RL, Dawber M. In situ X-ray diffraction and the evolution of polarization during the growth of ferroelectric superlattices. Nat Commun 2015; 6:10136. [PMID: 26634894 PMCID: PMC4686826 DOI: 10.1038/ncomms10136] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2015] [Accepted: 11/06/2015] [Indexed: 11/25/2022] Open
Abstract
In epitaxially strained ferroelectric thin films and superlattices, the ferroelectric transition temperature can lie above the growth temperature. Ferroelectric polarization and domains should then evolve during the growth of a sample, and electrostatic boundary conditions may play an important role. In this work, ferroelectric domains, surface termination, average lattice parameter and bilayer thickness are simultaneously monitored using in situ synchrotron X-ray diffraction during the growth of BaTiO3/SrTiO3 superlattices on SrTiO3 substrates by off-axis radio frequency magnetron sputtering. The technique used allows for scan times substantially faster than the growth of a single layer of material. Effects of electric boundary conditions are investigated by growing the same superlattice alternatively on SrTiO3 substrates and 20 nm SrRuO3 thin films on SrTiO3 substrates. These experiments provide important insights into the formation and evolution of ferroelectric domains when the sample is ferroelectric during the growth process.
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Affiliation(s)
- Benjamin Bein
- Department of Physics and Astronomy, Stony Brook University, Stony Brook, New York 11794-3800, USA
| | - Hsiang-Chun Hsing
- Department of Physics and Astronomy, Stony Brook University, Stony Brook, New York 11794-3800, USA
| | - Sara J. Callori
- Department of Physics and Astronomy, Stony Brook University, Stony Brook, New York 11794-3800, USA
| | - John Sinsheimer
- Department of Physics and Astronomy, Stony Brook University, Stony Brook, New York 11794-3800, USA
| | - Priya V. Chinta
- Department of Physics, Cook Physical Science Building, University of Vermont, Burlington, Vermont 05405, USA
| | - Randall L. Headrick
- Department of Physics, Cook Physical Science Building, University of Vermont, Burlington, Vermont 05405, USA
| | - Matthew Dawber
- Department of Physics and Astronomy, Stony Brook University, Stony Brook, New York 11794-3800, USA
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28
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Maurya D, Sun FC, Alpay SP, Priya S. A new method for achieving enhanced dielectric response over a wide temperature range. Sci Rep 2015; 5:15144. [PMID: 26477391 PMCID: PMC4609923 DOI: 10.1038/srep15144] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2015] [Accepted: 09/21/2015] [Indexed: 11/29/2022] Open
Abstract
We report a novel approach for achieving high dielectric response over a wide temperature range. In this approach, multilayer ceramic heterostructures with constituent compositions having strategically tuned Curie points (TC) were designed and integrated with varying electrical connectivity. Interestingly, these multilayer structures exhibited different dielectric behavior in series and parallel configuration due to variations in electrical boundary conditions resulting in the differences in the strength of the electrostatic coupling. The results are explained using nonlinear thermodynamic model taking into account electrostatic interlayer interaction. We believe that present work will have huge significance in design of high performance ceramic capacitors.
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Affiliation(s)
- Deepam Maurya
- Bio-inspired Materials and Devices Laboratory (BMDL), Center for Energy Harvesting Materials and Systems (CEHMS), Virginia Tech, 24061 USA
| | - Fu-Chang Sun
- Department of Materials Science &Engineering, Department of Physics, Institute of Materials Science, University of Connecticut, Storrs, CT 06269-3136, USA
| | - S Pamir Alpay
- Department of Materials Science &Engineering, Department of Physics, Institute of Materials Science, University of Connecticut, Storrs, CT 06269-3136, USA
| | - Shashank Priya
- Bio-inspired Materials and Devices Laboratory (BMDL), Center for Energy Harvesting Materials and Systems (CEHMS), Virginia Tech, 24061 USA
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29
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Lemée N, Infante IC, Hubault C, Boulle A, Blanc N, Boudet N, Demange V, Karkut MG. Polarization Rotation in Ferroelectric Tricolor PbTiO3/SrTiO3/PbZr0.2Ti0.8O3 Superlattices. ACS APPLIED MATERIALS & INTERFACES 2015; 7:19906-19913. [PMID: 26315344 DOI: 10.1021/acsami.5b03456] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
In ferroelectric thin films, controlling the orientation of the polarization is a key element to controlling their physical properties. We use laboratory and synchrotron X-ray diffraction to investigate ferroelectric bicolor PbTiO3/PbZr0.2Ti0.8O3 and tricolor PbTiO3/SrTiO3/PbZr0.2Ti0.8O3 superlattices and to study the role of the SrTiO3 layers on the domain structure. In the tricolor superlattices, we demonstrate the existence of 180° ferroelectric stripe nanodomains, induced by the depolarization field produced by the SrTiO3 layers. Each ultrathin SrTiO3 layer modifies the electrostatic boundary conditions between the ferroelectric layers compared to the corresponding bicolor structures, leading to the suppression of the a/c polydomain states. Combined with the electrostatic effect, the tensile strain induced by PbZr0.2Ti0.8O3 in the PbTiO3 layers leads to polarization rotation in the system as evidenced by grazing incidence X-ray measurements. This polarization rotation is associated with the monoclinic Mc phase as revealed by the splitting of the (HHL) and (H0L) reciprocal lattice points. This work demonstrates that the tricolor paraelectric/ferroelectric superlattices constitute a tunable system to investigate the concomitant effects of strains and depolarizing fields. Our studies provide a pathway to stabilize a monoclinic symmetry in ferroelectric layers, which is of particular interest for the enhancement of the piezoelectric properties.
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Affiliation(s)
- Nathalie Lemée
- Laboratoire de Physique de la Matière Condensée, EA 2081, Université de Picardie Jules Verne , 80039 Amiens, France
| | - Ingrid C Infante
- Laboratoire Structures, Propriétés et Modélisation des Solides, CentraleSupélec, CNRS-UMR 8580, Université Paris-Saclay , 92295 Cedex Châtenay-Malabry, France
| | - Cécile Hubault
- Laboratoire de Physique de la Matière Condensée, EA 2081, Université de Picardie Jules Verne , 80039 Amiens, France
| | - Alexandre Boulle
- Sciences des Procédés Céramiques et de Traitements de Surface, CNRS UMR 7315, Centre Européen de la Céramique , 87068 Limoges, France
| | - Nils Blanc
- University of Grenoble Alpes, Institut NEEL , F-38000 Grenoble, France
- CNRS, Institut NEEL , F-38042 Grenoble, France
| | - Nathalie Boudet
- University of Grenoble Alpes, Institut NEEL , F-38000 Grenoble, France
- CNRS, Institut NEEL , F-38042 Grenoble, France
| | - Valérie Demange
- Institut des Sciences Chimiques de Rennes, UMR 6226 CNRS/Université de Rennes 1 , Campus de Beaulieu, 35042 Rennes, France
| | - Michael G Karkut
- Laboratoire de Physique de la Matière Condensée, EA 2081, Université de Picardie Jules Verne , 80039 Amiens, France
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30
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Fabrizi F, Thomas PA, Nisbet G, Collins SP. Identification of inversion domains in KTiOPO4 via resonant X-ray diffraction. Acta Crystallogr A Found Adv 2015; 71:361-7. [PMID: 25970297 PMCID: PMC4487424 DOI: 10.1107/s2053273315007238] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2015] [Accepted: 04/11/2015] [Indexed: 12/02/2022] Open
Abstract
A novel method is presented for the identification of the absolute crystallographic structure in multi-domain polar materials such as ferroelectric KTiOPO4. Resonant (or 'anomalous') X-ray diffraction spectra collected across the absorption K edge of Ti (4.966 keV) on a single Bragg reflection demonstrate a huge intensity ratio above and below the edge, providing a polar domain contrast of ∼270. This allows one to map the spatial domain distribution in a periodically inverted sample, with a resolution of ∼1 µm achieved with a microfocused beam. This non-contact, non-destructive technique is well suited for samples of large dimensions (in contrast with traditional resonant X-ray methods based on diffraction from Friedel pairs), and its potential is particularly relevant in the context of physical phenomena connected with an absence of inversion symmetry, which require characterization of the underlying absolute atomic structure (such as in the case of magnetoelectric coupling and multiferroics).
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Affiliation(s)
- Federica Fabrizi
- Diamond Light Source, Harwell Science and Innovation Campus, Didcot, OX11 0DE, England
| | - Pamela A. Thomas
- Department of Physics, University of Warwick, Coventry, CV4 7AL, England
| | - Gareth Nisbet
- Diamond Light Source, Harwell Science and Innovation Campus, Didcot, OX11 0DE, England
| | - Stephen P. Collins
- Diamond Light Source, Harwell Science and Innovation Campus, Didcot, OX11 0DE, England
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31
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Xu R, Liu S, Grinberg I, Karthik J, Damodaran AR, Rappe AM, Martin LW. Ferroelectric polarization reversal via successive ferroelastic transitions. NATURE MATERIALS 2015; 14:79-86. [PMID: 25344784 DOI: 10.1038/nmat4119] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2013] [Accepted: 09/23/2014] [Indexed: 06/04/2023]
Abstract
Switchable polarization makes ferroelectrics a critical component in memories, actuators and electro-optic devices, and potential candidates for nanoelectronics. Although many studies of ferroelectric switching have been undertaken, much remains to be understood about switching in complex domain structures and in devices. In this work, a combination of thin-film epitaxy, macro- and nanoscale property and switching characterization, and molecular dynamics simulations are used to elucidate the nature of switching in PbZr(0.2)Ti(0.8)O3 thin films. Differences are demonstrated between (001)-/(101)- and (111)-oriented films, with the latter exhibiting complex, nanotwinned ferroelectric domain structures with high densities of 90° domain walls and considerably broadened switching characteristics. Molecular dynamics simulations predict both 180° (for (001)-/(101)-oriented films) and 90° multi-step switching (for (111)-oriented films) and these processes are subsequently observed in stroboscopic piezoresponse force microscopy. These results have implications for our understanding of ferroelectric switching and offer opportunities to change domain reversal speed.
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Affiliation(s)
- Ruijuan Xu
- Department of Materials Science and Engineering, University of California, Berkeley, California 94720, USA
| | - Shi Liu
- The Makineni Theoretical Laboratories, Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6323, USA
| | - Ilya Grinberg
- The Makineni Theoretical Laboratories, Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6323, USA
| | - J Karthik
- Department of Materials Science and Engineering, University of California, Berkeley, California 94720, USA
| | - Anoop R Damodaran
- Department of Materials Science and Engineering, University of California, Berkeley, California 94720, USA
| | - Andrew M Rappe
- The Makineni Theoretical Laboratories, Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6323, USA
| | - Lane W Martin
- 1] Department of Materials Science and Engineering, University of California, Berkeley, California 94720, USA [2] Materials Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
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32
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Lichtensteiger C, Fernandez-Pena S, Weymann C, Zubko P, Triscone JM. Tuning of the depolarization field and nanodomain structure in ferroelectric thin films. NANO LETTERS 2014; 14:4205-11. [PMID: 24983128 DOI: 10.1021/nl404734z] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
The screening efficiency of a metal-ferroelectric interface plays a critical role in determining the polarization stability and hence the functional properties of ferroelectric thin films. Imperfect screening leads to strong depolarization fields that reduce the spontaneous polarization or drive the formation of ferroelectric domains. We demonstrate that by modifying the screening at the metal-ferroelectric interface through insertion of ultrathin dielectric spacers, the strength of the depolarization field can be tuned and thus used to control the formation of nanoscale domains. Using piezoresponse force microscopy, we follow the evolution of the domain configurations as well as polarization stability as a function of depolarization field strength.
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Affiliation(s)
- Céline Lichtensteiger
- DPMC - University of Geneva , 24 Quai Ernest Ansermet, CH-1211 Geneva 4, Switzerland
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33
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Wojdeł JC, Íñiguez J. Ferroelectric transitions at ferroelectric domain walls found from first principles. PHYSICAL REVIEW LETTERS 2014; 112:247603. [PMID: 24996110 DOI: 10.1103/physrevlett.112.247603] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2014] [Indexed: 06/03/2023]
Abstract
We present a first-principles study of model domain walls (DWs) in prototypic ferroelectric PbTiO(3). At high temperature the DW structure is somewhat trivial, with atoms occupying high-symmetry positions. However, upon cooling the DW undergoes a symmetry-breaking transition characterized by a giant dielectric anomaly and the onset of a large and switchable polarization. Our results thus corroborate previous arguments for the occurrence of ferroic orders at structural DWs, providing a detailed atomistic picture of a temperature-driven DW-confined transformation. Beyond its relevance to the field of ferroelectrics, our results highlight the interest of these DWs in the broader areas of low-dimensional physics and phase transitions in strongly fluctuating systems.
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Affiliation(s)
- Jacek C Wojdeł
- Institut de Ciència de Materials de Barcelona (ICMAB-CSIC), Campus UAB, 08193 Bellaterra, Spain
| | - Jorge Íñiguez
- Institut de Ciència de Materials de Barcelona (ICMAB-CSIC), Campus UAB, 08193 Bellaterra, Spain
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34
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Chang WY, Huang W, Bagal A, Chang CH, Tian J, Han P, Jiang X. Study on dielectric and piezoelectric properties of 0.7 Pb(Mg 1/3Nb 2/3)O 3-0.3 PbTiO 3 single crystal with nano-patterned composite electrode. JOURNAL OF APPLIED PHYSICS 2013; 114:114103. [PMID: 24170960 PMCID: PMC3790807 DOI: 10.1063/1.4821517] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/19/2013] [Accepted: 09/02/2013] [Indexed: 05/30/2023]
Abstract
Effect of nano-patterned composite electrode and backswitching poling technique on dielectric and piezoelectric properties of 0.7 Pb(Mg1/3Nb2/3)O3-0.3 PbTiO3 was studied in this paper. Composite electrode consists of Mn nano-patterns with pitch size of 200 nm, and a blanket layer of Ti/Au was fabricated using a nanolithography based lift-off process, heat treatment, and metal film sputtering. Composite electrode and backswitching poling resulted in 27% increase of d33 and 25% increase of dielectric constant, and we believe that this is attributed to regularly defined nano-domains and irreversible rhombohedral to monoclinic phase transition in crystal. The results indicate that nano-patterned composite electrode and backswitching poling has a great potential in domain engineering of relaxor single crystals for advanced devices.
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35
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Chen P, Cosgriff MP, Zhang Q, Callori SJ, Adams BW, Dufresne EM, Dawber M, Evans PG. Field-dependent domain distortion and interlayer polarization distribution in PbTiO3/SrTiO3 superlattices. PHYSICAL REVIEW LETTERS 2013; 110:047601. [PMID: 25166200 DOI: 10.1103/physrevlett.110.047601] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/05/2012] [Indexed: 06/03/2023]
Abstract
The remnant polarization of weakly coupled ferroelectric-dielectric superlattices is distributed unequally between the component layers, and as a result the components respond differently to applied electric fields. The difference is apparent in both the nanometer-scale structure of striped polarization domains and in the development of piezoelectric strain and field-induced polarization. Both effects are probed with in situ time-resolved synchrotron x-ray diffraction in a PbTiO(3)/SrTiO(3) superlattice in fields up to 2.38 MV/cm. Domains are initially distorted to increase the polarization in the SrTiO(3) layer while retaining the striped motif. The subsequent transformation to a uniform polarization state at a later time leads to piezoelectric expansion dominated by the field-induced polarization of the SrTiO(3) layers. The results are consistent with theoretical predictions of the field dependence of the domain structure and electrical polarization.
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Affiliation(s)
- Pice Chen
- Department of Materials Science and Engineering & Materials Science Program, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
| | - Margaret P Cosgriff
- Department of Materials Science and Engineering & Materials Science Program, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
| | - Qingteng Zhang
- Department of Materials Science and Engineering & Materials Science Program, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
| | - Sara J Callori
- Department of Physics and Astronomy, Stony Brook University, Stony Brook, New York 11794, USA
| | - Bernhard W Adams
- Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - Eric M Dufresne
- Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - Matthew Dawber
- Department of Physics and Astronomy, Stony Brook University, Stony Brook, New York 11794, USA
| | - Paul G Evans
- Department of Materials Science and Engineering & Materials Science Program, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
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36
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Kim JW, Thompson P, Brown S, Normile PS, Schlueter JA, Shkabko A, Weidenkaff A, Ryan PJ. Emergent superstructural dynamic order due to competing antiferroelectric and antiferrodistortive instabilities in bulk EuTiO3. PHYSICAL REVIEW LETTERS 2013; 110:027201. [PMID: 23383935 DOI: 10.1103/physrevlett.110.027201] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2012] [Indexed: 06/01/2023]
Abstract
Microscopic structural instabilities of EuTiO3 single crystals were investigated by synchrotron x-ray diffraction. Antiferrodistortive (AFD) oxygen octahedron rotational order was observed alongside Ti derived antiferroelectric distortions. The competition between the two instabilities is reconciled through a cooperatively modulated structure allowing both to coexist. The combination of electric and magnetic fields increases the population of the modulated AFD order, illustrating how the origin of the large magnetoelectric coupling derives from the dynamic equilibrium between AFD and polar instabilities.
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Affiliation(s)
- Jong-Woo Kim
- X-ray Science Division, Argonne National Laboratory, Argonne, Illinois 60439, USA.
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37
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Tayebi N, Kim S, Chen RJ, Tran Q, Franklin N, Nishi Y, Ma Q, Rao V. Tuning the built-in electric field in ferroelectric Pb(Zr(0.2)Ti(0.8))O3 films for long-term stability of single-digit nanometer inverted domains. NANO LETTERS 2012; 12:5455-5463. [PMID: 23043427 DOI: 10.1021/nl302911k] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
The emergence of new technologies, such as whole genome sequencing systems, which generate a large amount of data, is requiring ultrahigh storage capacities. Due to their compactness and low power consumption, probe-based memory devices using Pb(Zr(0.2)Ti(0.8))O(3) (PZT) ferroelectric films are the ideal candidate for such applications where portability is desired. To achieve ultrahigh (>1 Tbit/in(2)) storage densities, sub-10 nm inverted domains are required. However, such domains remain unstable and can invert back to their original polarization due to the effects of an antiparallel built-in electric field in the PZT film, domain-wall, and depolarization energies. Here, we show that the built-in electric-field can be tuned and suppressed by repetitive hydrogen and oxygen plasma treatments. Such treatments trigger reversible Pb reduction/oxidation activity, which alters the electrochemistry of the Pb overlayer and compensates for charges induced by the Pb vacancies. This tuning mechanism is used to demonstrate the writing of stable and equal size sub-4 nm domains in both up- and down-polarized PZT films, corresponding to eight inverted unit-cells. The bit sizes recorded here are the smallest ever achieved, which correspond to potential 60 Tbit/in(2) data storage densities.
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Affiliation(s)
- Noureddine Tayebi
- Intel Corporation, 2200 Mission College Boulevard, Santa Clara, California 95054, USA.
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38
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Callori SJ, Gabel J, Su D, Sinsheimer J, Fernandez-Serra MV, Dawber M. Ferroelectric PbTiO3/SrRuO3 superlattices with broken inversion symmetry. PHYSICAL REVIEW LETTERS 2012; 109:067601. [PMID: 23006304 DOI: 10.1103/physrevlett.109.067601] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/13/2012] [Indexed: 06/01/2023]
Abstract
We have fabricated PbTiO3/SrRuO3 superlattices with ultrathin SrRuO3 layers. Because of the superlattice geometry, the samples show a large anisotropy in their electrical resistivity, which can be controlled by changing the thickness of the PbTiO3 layers. Therefore, along the ferroelectric direction, SrRuO3 layers can act as dielectric, rather than metallic, elements. We show that, by reducing the concentration of PbTiO3, an increasingly important effect of polarization asymmetry due to compositional inversion symmetry breaking occurs. The results are significant as they represent a new class of ferroelectric superlattices, with a rich and complex phase diagram. By expanding our set of materials we are able to introduce new behaviors that can only occur when one of the materials is not a perovskite titanate. Here, compositional inversion symmetry breaking in bicolor superlattices, due to the combined variation of A and B site ions within the superlattice, is demonstrated using a combination of experimental measurements and first principles density functional theory.
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Affiliation(s)
- S J Callori
- Department of Physics and Astronomy, Stony Brook University, Stony Brook, New York 11794-3800, USA
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39
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Zubko P, Jecklin N, Torres-Pardo A, Aguado-Puente P, Gloter A, Lichtensteiger C, Junquera J, Stéphan O, Triscone JM. Electrostatic coupling and local structural distortions at interfaces in ferroelectric/paraelectric superlattices. NANO LETTERS 2012; 12:2846-2851. [PMID: 22591200 DOI: 10.1021/nl3003717] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
The performance of ferroelectric devices is intimately entwined with the structure and dynamics of ferroelectric domains. In ultrathin ferroelectrics, ordered nanodomains arise naturally in response to the presence of a depolarizing field and give rise to highly inhomogeneous polarization and structural profiles. Ferroelectric superlattices offer a unique way of engineering the desired nanodomain structure by modifying the strength of the electrostatic interactions between different ferroelectric layers. Through a combination of X-ray diffraction, transmission electron microscopy, and first-principles calculations, the electrostatic coupling between ferroelectric layers is studied, revealing the existence of interfacial layers of reduced tetragonality attributed to inhomogeneous strain and polarization profiles associated with the domain structure.
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Affiliation(s)
- P Zubko
- DPMC, University of Geneva, 24 quai Ernest-Ansermet, 1211 Geneva-4, Switzerland.
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40
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Aguado-Puente P, García-Fernández P, Junquera J. Interplay of couplings between antiferrodistortive, ferroelectric, and strain degrees of freedom in monodomain PbTiO3/SrTiO3 superlattices. PHYSICAL REVIEW LETTERS 2011; 107:217601. [PMID: 22181925 DOI: 10.1103/physrevlett.107.217601] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2011] [Indexed: 05/31/2023]
Abstract
We report first-principles calculations on the coupling between epitaxial strain, polarization, and oxygen octahedra rotations in monodomain (PbTiO(3))(n)/(SrTiO(3))(n) superlattices. We show how the interplay between (i) the epitaxial strain and (ii) the electrostatic conditions can be used to control the orientation of the main axis of the system. The electrostatic constrains at the interface facilitate the polarization rotation and, as a consequence, we predict large piezoelectric responses at epitaxial strains smaller than those required considering only strain effects. In addition, ferroelectric (FE) and antiferrodistortive (AFD) modes are strongly coupled. Usual steric arguments cannot explain this coupling and a covalent model is proposed to account for it. The energy gain due to the FE-AFD coupling decreases with the periodicity of the superlattice, becoming negligible for n ≥ 3.
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Affiliation(s)
- Pablo Aguado-Puente
- Departamento de Ciencias de la Tierra y Física de la Materia Condensada, Universidad de Cantabria, Cantabria Campus Internacional, Santander, Spain
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41
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Highland MJ, Fister TT, Fong DD, Fuoss PH, Thompson C, Eastman JA, Streiffer SK, Stephenson GB. Equilibrium polarization of ultrathin PbTiO3 with surface compensation controlled by oxygen partial pressure. PHYSICAL REVIEW LETTERS 2011; 107:187602. [PMID: 22107673 DOI: 10.1103/physrevlett.107.187602] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2011] [Indexed: 05/31/2023]
Abstract
We present a synchrotron x-ray study of the equilibrium polarization structure of ultrathin PbTiO(3) films on SrRuO(3) electrodes epitaxially grown on SrTiO(3) (001) substrates, as a function of temperature and the external oxygen partial pressure (pO(2)) controlling their surface charge compensation. We find that the ferroelectric Curie temperature (T(C)) varies with pO(2) and has a minimum at the intermediate pO(2), where the polarization below T(C) changes sign. The experiments are in qualitative agreement with a model based on Landau theory that takes into account the interaction of the phase transition with the electrochemical equilibria for charged surface species. The paraelectric phase is stabilized at intermediate pO(2) when the concentrations of surface species are insufficient to compensate either polar orientation.
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Affiliation(s)
- M J Highland
- Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439, USA.
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Jo JY, Chen P, Sichel RJ, Callori SJ, Sinsheimer J, Dufresne EM, Dawber M, Evans PG. Nanosecond dynamics of ferroelectric/dielectric superlattices. PHYSICAL REVIEW LETTERS 2011; 107:055501. [PMID: 21867078 DOI: 10.1103/physrevlett.107.055501] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/15/2011] [Indexed: 05/31/2023]
Abstract
The nanosecond response of a PbTiO(3)/SrTiO(3) ferroelectric/dielectric superlattice to applied electric fields is closely linked to the dynamics of striped domains of the remnant polarization. The intensity of domain satellite reflections observed with time-resolved x-ray microdiffraction decays in 5-100 ns depending on the magnitude of the electric field. The piezoelectric response of the superlattice within stripe domains is strongly suppressed due to electromechanical clamping between adjacent regions of opposite polarization. Regions of the superlattice that have been switched into a uniform polarization state by the applied electric field, however, exhibit piezoelectricity during the course of the switching process. We propose a switching model different from previous models of the switching of superlattices, based instead on a spatially heterogeneous transformation between striped and uniform polarization states.
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Affiliation(s)
- Ji Young Jo
- Department of Materials Science and Engineering and Materials Science Program, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
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