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Noor A, Damodaran AR, Lee IH, Maier SA, Oh SH, Ciracì C. Mode-Matching Enhancement of Second-Harmonic Generation with Plasmonic Nanopatch Antennas. ACS Photonics 2020; 7:3333-3340. [PMID: 33365359 PMCID: PMC7747867 DOI: 10.1021/acsphotonics.0c01545] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/05/2020] [Indexed: 05/06/2023]
Abstract
Plasmonic enhancement of nonlinear optical processes confront severe limitations arising from the strong dispersion of metal susceptibilities and small interaction volumes that hamper the realization of desirable phase-matching-like conditions. Maximizing nonlinear interactions in nanoscale systems require simultaneous excitation of resonant modes that spatially and constructively overlap at all wavelengths involved in the process. Here, we present a hybrid rectangular patch antenna design for optimal second-harmonic generation (SHG) that is characterized by a non-centrosymmetric dielectric/ferroelectric material at the plasmonic hot spot. The optimization of the rectangular patch allows for the independent tuning of various modes of resonances that can be used to enhance the SHG process. We explore the angular dependence of SHG in these hybrid structures and highlight conditions necessary for the maximal SHG efficiency. Furthermore, we propose a novel configuration with a periodically poled ferroelectric layer for an orders-of-magnitude enhanced SHG at normal incidence. Such a platform may enable the development of integrated nanoscale light sources and on-chip frequency converters.
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Affiliation(s)
- Ahsan Noor
- Center
for Biomolecular Nanotechnologies, Istituto
Italiano di Tecnologia, Via Barsanti 14, Arnesano 73010, Italy
- Dipartimento
di Ingegneria Elettrica e dell’Informazione, Politecnico di Bari, Via Re David 200, Bari 70125, Italy
| | - Anoop R. Damodaran
- Department
of Electrical and Computer Engineering, University of Minnesota, Minneapolis 55455, Minnesota, United States
- (A.R.D.)
| | - In-Ho Lee
- Department
of Electrical and Computer Engineering, University of Minnesota, Minneapolis 55455, Minnesota, United States
| | - Stefan A. Maier
- Chair
in Hybrid Nanosystems, Nanoinstitut Munich, Faculty of Physics, Ludwig-Maximilians Universität München, Königinstrasse 10, München 80539, Germany
- Experimental
Solid State Physics Group, Department of Physics, Imperial College London, London SW7 2AZ, UK
| | - Sang-Hyun Oh
- Department
of Electrical and Computer Engineering, University of Minnesota, Minneapolis 55455, Minnesota, United States
| | - Cristian Ciracì
- Center
for Biomolecular Nanotechnologies, Istituto
Italiano di Tecnologia, Via Barsanti 14, Arnesano 73010, Italy
- (C.C.)
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2
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Kim J, Takenaka H, Qi Y, Damodaran AR, Fernandez A, Gao R, McCarter MR, Saremi S, Chung L, Rappe AM, Martin LW. Epitaxial Strain Control of Relaxor Ferroelectric Phase Evolution. Adv Mater 2019; 31:e1901060. [PMID: 30968488 DOI: 10.1002/adma.201901060] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2019] [Revised: 03/15/2019] [Indexed: 06/09/2023]
Abstract
Understanding and ultimately controlling the large electromechanical effects in relaxor ferroelectrics requires intimate knowledge of how the local-polar order evolves under applied stimuli. Here, the biaxial-strain-induced evolution of and correlations between polar structures and properties in epitaxial films of the prototypical relaxor ferroelectric 0.68PbMg1/3 Nb2/3 O3 -0.32PbTiO3 are investigated. X-ray diffuse-scattering studies reveal an evolution from a butterfly- to disc-shaped pattern and an increase in the correlation-length from ≈8 to ≈25 nm with increasing compressive strain. Molecular-dynamics simulations reveal the origin of the changes in the diffuse-scattering patterns and that strain induces polarization rotation and the merging of the polar order. As the magnitude of the strain is increased, relaxor behavior is gradually suppressed but is not fully quenched. Analysis of the dynamic evolution of dipole alignment in the simulations reveals that, while, for most unit-cell chemistries and configurations, strain drives a tendency toward more ferroelectric-like order, there are certain unit cells that become more disordered under strain, resulting in stronger competition between ordered and disordered regions and enhanced overall susceptibilities. Ultimately, this implies that deterministic creation of specific local chemical configurations could be an effective way to enhance relaxor performance.
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Affiliation(s)
- Jieun Kim
- Department of Materials Science and Engineering, University of California, Berkeley, Berkeley, CA, 94720, USA
| | - Hiroyuki Takenaka
- Department of Physics, University of Nebraska, Lincoln, Lincoln, NE, 68588, USA
| | - Yubo Qi
- Department of Chemistry, University of Pennsylvania, Philadelphia, PA, 19104-6323, USA
| | - Anoop R Damodaran
- Department of Materials Science and Engineering, University of California, Berkeley, Berkeley, CA, 94720, USA
| | - Abel Fernandez
- Department of Materials Science and Engineering, University of California, Berkeley, Berkeley, CA, 94720, USA
| | - Ran Gao
- Department of Materials Science and Engineering, University of California, Berkeley, Berkeley, CA, 94720, USA
| | - Margaret R McCarter
- Department of Physics, University of California, Berkeley, Berkeley, CA, 94720, USA
| | - Sahar Saremi
- Department of Materials Science and Engineering, University of California, Berkeley, Berkeley, CA, 94720, USA
| | - Linh Chung
- Department of Materials Science and Engineering, University of California, Berkeley, Berkeley, CA, 94720, USA
| | - Andrew M Rappe
- Department of Chemistry, University of Pennsylvania, Philadelphia, PA, 19104-6323, USA
| | - Lane W Martin
- Department of Materials Science and Engineering, University of California, Berkeley, Berkeley, CA, 94720, USA
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
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3
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Stoica VA, Laanait N, Dai C, Hong Z, Yuan Y, Zhang Z, Lei S, McCarter MR, Yadav A, Damodaran AR, Das S, Stone GA, Karapetrova J, Walko DA, Zhang X, Martin LW, Ramesh R, Chen LQ, Wen H, Gopalan V, Freeland JW. Optical creation of a supercrystal with three-dimensional nanoscale periodicity. Nat Mater 2019; 18:377-383. [PMID: 30886403 DOI: 10.1038/s41563-019-0311-x] [Citation(s) in RCA: 48] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2018] [Accepted: 02/04/2019] [Indexed: 06/09/2023]
Abstract
Stimulation with ultrafast light pulses can realize and manipulate states of matter with emergent structural, electronic and magnetic phenomena. However, these non-equilibrium phases are often transient and the challenge is to stabilize them as persistent states. Here, we show that atomic-scale PbTiO3/SrTiO3 superlattices, counterpoising strain and polarization states in alternate layers, are converted by sub-picosecond optical pulses to a supercrystal phase. This phase persists indefinitely under ambient conditions, has not been created via equilibrium routes, and can be erased by heating. X-ray scattering and microscopy show this unusual phase consists of a coherent three-dimensional structure with polar, strain and charge-ordering periodicities of up to 30 nm. By adjusting only dielectric properties, the phase-field model describes this emergent phase as a photo-induced charge-stabilized supercrystal formed from a two-phase equilibrium state. Our results demonstrate opportunities for light-activated pathways to thermally inaccessible and emergent metastable states.
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Affiliation(s)
- V A Stoica
- Department of Materials Science and Engineering, Pennsylvania State University, University Park, PA, USA
| | - N Laanait
- Center for Nanophase Materials Sciences, Oak Ridge, TN, USA
| | - C Dai
- Department of Materials Science and Engineering, Pennsylvania State University, University Park, PA, USA
| | - Z Hong
- Department of Materials Science and Engineering, Pennsylvania State University, University Park, PA, USA
| | - Y Yuan
- Department of Materials Science and Engineering, Pennsylvania State University, University Park, PA, USA
| | - Z Zhang
- Advanced Photon Source, Argonne National Laboratory, Argonne, IL, USA
| | - S Lei
- Department of Materials Science and Engineering, Pennsylvania State University, University Park, PA, USA
| | - M R McCarter
- Department of Materials Science and Engineering, University of California, Berkeley, CA, USA
| | - A Yadav
- Department of Materials Science and Engineering, University of California, Berkeley, CA, USA
| | - A R Damodaran
- Department of Materials Science and Engineering, University of California, Berkeley, CA, USA
| | - S Das
- Department of Materials Science and Engineering, University of California, Berkeley, CA, USA
| | - G A Stone
- Department of Materials Science and Engineering, Pennsylvania State University, University Park, PA, USA
| | - J Karapetrova
- Advanced Photon Source, Argonne National Laboratory, Argonne, IL, USA
| | - D A Walko
- Advanced Photon Source, Argonne National Laboratory, Argonne, IL, USA
| | - X Zhang
- Advanced Photon Source, Argonne National Laboratory, Argonne, IL, 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
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - L-Q Chen
- Department of Materials Science and Engineering, Pennsylvania State University, University Park, PA, USA
| | - H Wen
- Advanced Photon Source, Argonne National Laboratory, Argonne, IL, USA
| | - V Gopalan
- Department of Materials Science and Engineering, Pennsylvania State University, University Park, PA, USA.
| | - J W Freeland
- Advanced Photon Source, Argonne National Laboratory, Argonne, IL, USA.
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4
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Manipatruni S, Nikonov DE, Lin CC, Prasad B, Huang YL, Damodaran AR, Chen Z, Ramesh R, Young IA. Voltage control of unidirectional anisotropy in ferromagnet-multiferroic system. Sci Adv 2018; 4:eaat4229. [PMID: 30480090 PMCID: PMC6251722 DOI: 10.1126/sciadv.aat4229] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2018] [Accepted: 10/25/2018] [Indexed: 05/12/2023]
Abstract
Demonstration of ultralow energy switching mechanisms is imperative for continued improvements in computing devices. Ferroelectric (FE) and multiferroic (MF) order and their manipulation promise an ideal combination of state variables to reach attojoule range for logic and memory (i.e., ~30× lower switching energy than nanoelectronics). In BiFeO3 (BFO), the coupling between the antiferromagnetic (AFM) and FE order is robust at room temperature, scalable in voltage, stabilized by the FE order, and can be integrated into a fabrication process for a beyond-CMOS (complementary metal-oxide semiconductor) era. The presence of the AFM order and a canted magnetic moment in this system causes exchange interaction with a ferromagnet such as Co0.9Fe0.1 or La0.7Sr0.3MnO3. Previous research has shown that exchange coupling (uniaxial anisotropy) can be controlled with an electric field. However, voltage modulation of unidirectional anisotropy, which is preferred for logic and memory technologies, has not yet been demonstrated. Here, we present evidence for electric field control of exchange bias of laterally scaled spin valves that is exchange coupled to BFO at room temperature. We show that the exchange bias in this bilayer is robust, electrically controlled, and reversible. We anticipate that magnetoelectricity at these scaled dimensions provides a powerful pathway for computing beyond modern nanoelectronics by enabling a new class of nonvolatile, ultralow energy computing elements.
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Affiliation(s)
| | | | - Chia-Ching Lin
- Components Research, Intel Corp., Hillsboro, OR 97124, USA
| | - Bhagwati Prasad
- Department of Materials Science and Engineering and Department of Physics, University of California, Berkeley, CA 94720, USA
| | - Yen-Lin Huang
- Department of Materials Science and Engineering and Department of Physics, University of California, Berkeley, CA 94720, USA
| | - Anoop R. Damodaran
- Department of Materials Science and Engineering and Department of Physics, University of California, Berkeley, CA 94720, USA
| | - Zuhuang Chen
- Department of Materials Science and Engineering and Department of Physics, University of California, Berkeley, CA 94720, USA
| | - Ramamoorthy Ramesh
- Department of Materials Science and Engineering and Department of Physics, University of California, Berkeley, CA 94720, USA
| | - Ian A. Young
- Components Research, Intel Corp., Hillsboro, OR 97124, USA
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5
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Xu R, Gao R, Reyes-Lillo SE, Saremi S, Dong Y, Lu H, Chen Z, Lu X, Qi Y, Hsu SL, Damodaran AR, Zhou H, Neaton JB, Martin LW. Reducing Coercive-Field Scaling in Ferroelectric Thin Films via Orientation Control. ACS Nano 2018; 12:4736-4743. [PMID: 29641177 DOI: 10.1021/acsnano.8b01399] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
The desire for low-power/voltage operation of devices is driving renewed interest in understanding scaling effects in ferroelectric thin films. As the dimensions of ferroelectrics are reduced, the properties can vary dramatically, including the robust scaling relationship between coercive field ( Ec) and thickness ( d), also referred to as the Janovec-Kay-Dunn (JKD) law, wherein Ec ∝ d-2/3. Here, we report that whereas (001)-oriented heterostructures follow JKD scaling across the thicknesses range of 20-330 nm, (111)-oriented heterostructures of the canonical tetragonal ferroelectric PbZr0.2Ti0.8O3 exhibit a deviation from JKD scaling wherein a smaller scaling exponent for the evolution of Ec is observed in films of thickness ≲ 165 nm. X-ray diffraction reveals that whereas (001)-oriented heterostructures remain tetragonal for all thicknesses, (111)-oriented heterostructures exhibit a transition from tetragonal-to-monoclinic symmetry in films of thickness ≲ 165 nm as a result of the compressive strain. First-principles calculations suggest that this symmetry change contributes to the deviation from the expected scaling, as the monoclinic phase has a lower energy barrier for switching. This structural evolution also gives rise to changes in the c/ a lattice parameter ratio, wherein this ratio increases and decreases in (001)- and (111)-oriented heterostructures, respectively, as the films are made thinner. In (111)-oriented heterostructures, this reduced tetragonality drives a reduction of the remanent polarization and, therefore, a reduction of the domain-wall energy and overall energy barrier to switching, which further exacerbates the deviation from the expected scaling. Overall, this work demonstrates a route toward reducing coercive fields in ferroelectric thin films and provides a possible mechanism to understand the deviation from JKD scaling.
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Affiliation(s)
- Ruijuan Xu
- Department of Materials Science and Engineering , University of California , Berkeley , California 94720 , United States
| | - Ran Gao
- Department of Materials Science and Engineering , University of California , Berkeley , California 94720 , United States
| | - Sebastian E Reyes-Lillo
- Departamento de Ciencias Físicas , Universidad Andres Bello , Santiago 837-0136 , Chile
- Department of Physics , University of California , Berkeley , California 94720 , United States
- Molecular Foundry , Lawrence Berkeley National Laboratory , Berkeley , California 94720 , United States
| | - Sahar Saremi
- Department of Materials Science and Engineering , University of California , Berkeley , California 94720 , United States
| | - Yongqi Dong
- National Synchrotron Radiation Laboratory and CAS Key Laboratory of Materials for Energy Conversion , University of Science and Technology of China , Hefei 230026 , China
| | - Hongling Lu
- Department of Materials Science and Engineering , University of California , Berkeley , California 94720 , United States
| | - Zuhuang Chen
- Department of Materials Science and Engineering , University of California , Berkeley , California 94720 , United States
| | - Xiaoyan Lu
- School of Civil Engineering , Harbin Institute of Technology , Harbin 150001 , China
| | - Yajun Qi
- Department of Materials Science and Engineering , Hubei University , Wuhan 430062 , China
| | - Shang-Lin Hsu
- Department of Materials Science and Engineering , University of California , Berkeley , California 94720 , United States
- Materials Sciences Division , Lawrence Berkeley National Laboratory , Berkeley , California 94720 , United States
| | - Anoop R Damodaran
- Department of Materials Science and Engineering , University of California , Berkeley , California 94720 , United States
| | - Hua Zhou
- X-ray Science Division, Advanced Photon Source , Argonne National Laboratory , Argonne , Illinois 60439 , United States
| | - Jeffrey B Neaton
- Department of Physics , University of California , Berkeley , California 94720 , United States
- Molecular Foundry , Lawrence Berkeley National Laboratory , Berkeley , California 94720 , United States
- Kavli Energy NanoScience Institute at Berkeley , Berkeley , California 94720 , United States
| | - Lane W Martin
- Department of Materials Science and Engineering , University of California , Berkeley , California 94720 , United States
- Materials Sciences Division , Lawrence Berkeley National Laboratory , Berkeley , California 94720 , United States
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6
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Li Q, Nelson CT, Hsu SL, Damodaran AR, Li LL, Yadav AK, McCarter M, Martin LW, Ramesh R, Kalinin SV. Quantification of flexoelectricity in PbTiO 3/SrTiO 3 superlattice polar vortices using machine learning and phase-field modeling. Nat Commun 2017; 8:1468. [PMID: 29133906 PMCID: PMC5684141 DOI: 10.1038/s41467-017-01733-8] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2017] [Accepted: 10/12/2017] [Indexed: 11/13/2022] Open
Abstract
Flexoelectricity refers to electric polarization generated by heterogeneous mechanical strains, namely strain gradients, in materials of arbitrary crystal symmetries. Despite more than 50 years of work on this effect, an accurate identification of its coupling strength remains an experimental challenge for most materials, which impedes its wide recognition. Here, we show the presence of flexoelectricity in the recently discovered polar vortices in PbTiO3/SrTiO3 superlattices based on a combination of machine-learning analysis of the atomic-scale electron microscopy imaging data and phenomenological phase-field modeling. By scrutinizing the influence of flexocoupling on the global vortex structure, we match theory and experiment using computer vision methodologies to determine the flexoelectric coefficients for PbTiO3 and SrTiO3. Our findings highlight the inherent, nontrivial role of flexoelectricity in the generation of emergent complex polarization morphologies and demonstrate a viable approach to delineating this effect, conducive to the deeper exploration of both topics. Flexoelectric coupling between strain gradients and polarization influences the physics of ferroelectric devices but it is difficult to directly probe its effects. Here, Li et al. use principal component analysis to compare STEM images with phase-field modeling and extract the flexoelectric contributions.
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Affiliation(s)
- Q Li
- Oak Ridge National Laboratory, Institute for Functional Imaging of Materials and Center for Nanophase Materials Science, Oak Ridge, TN, 37831, USA.
| | - C T Nelson
- Department of Materials Science and Engineering, University of California, Berkeley, CA, 94720, USA.,Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - S-L Hsu
- Department of Materials Science and Engineering, University of California, Berkeley, CA, 94720, USA
| | - A R Damodaran
- Department of Materials Science and Engineering, University of California, Berkeley, CA, 94720, USA
| | - L-L Li
- Oak Ridge National Laboratory, Institute for Functional Imaging of Materials and Center for Nanophase Materials Science, Oak Ridge, TN, 37831, USA
| | - A K Yadav
- Department of Materials Science and Engineering, University of California, Berkeley, CA, 94720, USA
| | - M McCarter
- Department of Physics, University of California, Berkeley, CA, 94720, USA
| | - L W Martin
- Department of Materials Science and Engineering, University of California, Berkeley, CA, 94720, USA.,Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - R Ramesh
- Department of Materials Science and Engineering, University of California, Berkeley, CA, 94720, USA
| | - S V Kalinin
- Oak Ridge National Laboratory, Institute for Functional Imaging of Materials and Center for Nanophase Materials Science, Oak Ridge, TN, 37831, USA.
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7
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Damodaran AR, Pandya S, Agar JC, Cao Y, Vasudevan RK, Xu R, Saremi S, Li Q, Kim J, McCarter MR, Dedon LR, Angsten T, Balke N, Jesse S, Asta M, Kalinin SV, Martin LW. Three-State Ferroelastic Switching and Large Electromechanical Responses in PbTiO 3 Thin Films. Adv Mater 2017; 29:1702069. [PMID: 28758269 DOI: 10.1002/adma.201702069] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/12/2017] [Revised: 06/04/2017] [Indexed: 06/07/2023]
Abstract
Leveraging competition between energetically degenerate states to achieve large field-driven responses is a hallmark of functional materials, but routes to such competition are limited. Here, a new route to such effects involving domain-structure competition is demonstrated, which arises from strain-induced spontaneous partitioning of PbTiO3 thin films into nearly energetically degenerate, hierarchical domain architectures of coexisting c/a and a1 /a2 domain structures. Using band-excitation piezoresponse force microscopy, this study manipulates and acoustically detects a facile interconversion of different ferroelastic variants via a two-step, three-state ferroelastic switching process (out-of-plane polarized c+ → in-plane polarized a → out-of-plane polarized c- state), which is concomitant with large nonvolatile electromechanical strains (≈1.25%) and tunability of the local piezoresponse and elastic modulus (>23%). It is further demonstrated that deterministic, nonvolatile writing/erasure of large-area patterns of this electromechanical response is possible, thus showing a new pathway to improved function and properties.
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Affiliation(s)
- Anoop R Damodaran
- Department of Materials Science & Engineering, University of California, Berkeley, CA, 94720, USA
| | - Shishir Pandya
- Department of Materials Science & Engineering, University of California, Berkeley, CA, 94720, USA
| | - Josh C Agar
- Department of Materials Science & Engineering, University of California, Berkeley, CA, 94720, USA
| | - Ye Cao
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - Rama K Vasudevan
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
- Institute for Functional Imaging of Materials, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - Ruijuan Xu
- Department of Materials Science & Engineering, University of California, Berkeley, CA, 94720, USA
| | - Sahar Saremi
- Department of Materials Science & Engineering, University of California, Berkeley, CA, 94720, USA
| | - Qian Li
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - Jieun Kim
- Department of Materials Science & Engineering, University of California, Berkeley, CA, 94720, USA
| | | | - Liv R Dedon
- Department of Materials Science & Engineering, University of California, Berkeley, CA, 94720, USA
| | - Tom Angsten
- Department of Materials Science & Engineering, University of California, Berkeley, CA, 94720, USA
| | - Nina Balke
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
- Institute for Functional Imaging of Materials, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - Stephen Jesse
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
- Institute for Functional Imaging of Materials, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - Mark Asta
- Department of Materials Science & Engineering, University of California, Berkeley, CA, 94720, USA
| | - Sergei V Kalinin
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
- Institute for Functional Imaging of Materials, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - Lane W Martin
- Department of Materials Science & Engineering, University of California, Berkeley, CA, 94720, USA
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
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8
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Damodaran AR, Clarkson JD, Hong Z, Liu H, Yadav AK, Nelson CT, Hsu SL, McCarter MR, Park KD, Kravtsov V, Farhan A, Dong Y, Cai Z, Zhou H, Aguado-Puente P, García-Fernández P, Íñiguez J, Junquera J, Scholl A, Raschke MB, Chen LQ, Fong DD, Ramesh R, Martin LW. Phase coexistence and electric-field control of toroidal order in oxide superlattices. Nat Mater 2017; 16:1003-1009. [PMID: 28783161 DOI: 10.1038/nmat4951] [Citation(s) in RCA: 64] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/17/2016] [Accepted: 06/28/2017] [Indexed: 06/07/2023]
Abstract
Systems that exhibit phase competition, order parameter coexistence, and emergent order parameter topologies constitute a major part of modern condensed-matter physics. Here, by applying a range of characterization techniques, and simulations, we observe that in PbTiO3/SrTiO3 superlattices all of these effects can be found. By exploring superlattice period-, temperature- and field-dependent evolution of these structures, we observe several new features. First, it is possible to engineer phase coexistence mediated by a first-order phase transition between an emergent, low-temperature vortex phase with electric toroidal order and a high-temperature ferroelectric a1/a2 phase. At room temperature, the coexisting vortex and ferroelectric phases form a mesoscale, fibre-textured hierarchical superstructure. The vortex phase possesses an axial polarization, set by the net polarization of the surrounding ferroelectric domains, such that it possesses a multi-order-parameter state and belongs to a class of gyrotropic electrotoroidal compounds. Finally, application of electric fields to this mixed-phase system permits interconversion between the vortex and the ferroelectric phases concomitant with order-of-magnitude changes in piezoelectric and nonlinear optical responses. Our findings suggest new cross-coupled functionalities.
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Affiliation(s)
- A R Damodaran
- Department of Materials Science and Engineering, University of California, Berkeley, California 94720, USA
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - J D Clarkson
- Department of Materials Science and Engineering, University of California, Berkeley, California 94720, USA
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - Z Hong
- Department of Materials Science and Engineering, Pennsylvania State University, State College, Pennsylvania 16802, USA
| | - H Liu
- Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - A K Yadav
- Department of Materials Science and Engineering, University of California, Berkeley, California 94720, USA
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
- School of Electrical Engineering and Computer Science, UC Berkeley, Berkeley, California 94720, USA
| | - C T Nelson
- Department of Materials Science and Engineering, University of California, Berkeley, California 94720, USA
- National Center for Electron Microscopy, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - S-L Hsu
- Department of Materials Science and Engineering, University of California, Berkeley, California 94720, USA
- National Center for Electron Microscopy, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - M R McCarter
- Department of Physics, University of California, Berkeley, Berkeley, California 94720, USA
| | - K-D Park
- Department of Physics, Department of Chemistry, and JILA, University of Colorado, Boulder, Boulder, Colorado 80309, USA
| | - V Kravtsov
- Department of Physics, Department of Chemistry, and JILA, University of Colorado, Boulder, Boulder, Colorado 80309, USA
| | - A Farhan
- Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - Y Dong
- Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - Z Cai
- X-ray Science Division, Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - H Zhou
- X-ray Science Division, Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - P Aguado-Puente
- Centro de Física de Materiales, Universidad del País Vasco, 20018 San Sebastián, Spain
- Donostia International Physics Center, 20018 San Sebastián, Spain
| | - P García-Fernández
- Departmento de Ciencias de la Tierra y Física de la Materia Condensada, Universidad de Cantabria, Cantabria Campus Internacional, avenida de los Castros s/n, 39005 Santander, Spain
| | - J Íñiguez
- Materials Research and Technology Department, Luxembourg Institute of Science and Technology (LIST), 5 avenue des Hauts-Fourneaux, L-4362 Esch/Alzette, Luxembourg
| | - J Junquera
- Departmento de Ciencias de la Tierra y Física de la Materia Condensada, Universidad de Cantabria, Cantabria Campus Internacional, avenida de los Castros s/n, 39005 Santander, Spain
| | - A Scholl
- Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - M B Raschke
- Department of Physics, Department of Chemistry, and JILA, University of Colorado, Boulder, Boulder, Colorado 80309, USA
| | - L-Q Chen
- Department of Materials Science and Engineering, Pennsylvania State University, State College, Pennsylvania 16802, USA
| | - D D Fong
- Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - R Ramesh
- Department of Materials Science and Engineering, University of California, Berkeley, California 94720, USA
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
- Department of Physics, University of California, Berkeley, Berkeley, California 94720, USA
| | - L W Martin
- Department of Materials Science and Engineering, University of California, Berkeley, California 94720, USA
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
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9
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Hong Z, Damodaran AR, Xue F, Hsu SL, Britson J, Yadav AK, Nelson CT, Wang JJ, Scott JF, Martin LW, Ramesh R, Chen LQ. Stability of Polar Vortex Lattice in Ferroelectric Superlattices. Nano Lett 2017; 17:2246-2252. [PMID: 28240913 DOI: 10.1021/acs.nanolett.6b04875] [Citation(s) in RCA: 54] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
A novel mesoscale state comprising of an ordered polar vortex lattice has been demonstrated in ferroelectric superlattices of PbTiO3/SrTiO3. Here, we employ phase-field simulations, analytical theory, and experimental observations to evaluate thermodynamic conditions and geometric length scales that are critical for the formation of such exotic vortex states. We show that the stability of these vortex lattices involves an intimate competition between long-range electrostatic, long-range elastic, and short-range polarization gradient-related interactions leading to both an upper and a lower bound to the length scale at which these states can be observed. We found that the critical length is related to the intrinsic domain wall width, which could serve as a simple intuitive design rule for the discovery of novel ultrafine topological structures in ferroic systems.
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Affiliation(s)
- Zijian Hong
- Department of Materials Science and Engineering, The Pennsylvania State University , University Park, Pennsylvania 16802, United States
| | - Anoop R Damodaran
- Department of Materials Science and Engineering, University of California , Berkeley, California 94720, United States
| | - Fei Xue
- Department of Materials Science and Engineering, The Pennsylvania State University , University Park, Pennsylvania 16802, United States
| | - Shang-Lin Hsu
- Department of Materials Science and Engineering, University of California , Berkeley, California 94720, United States
- Materials Sciences Division, Lawrence Berkeley National Laboratory , Berkeley, California 94720, United States
- Department of Physics, University of California , Berkeley, California 94720, United States
| | - Jason Britson
- Department of Materials Science and Engineering, The Pennsylvania State University , University Park, Pennsylvania 16802, United States
| | - Ajay K Yadav
- Department of Materials Science and Engineering, University of California , Berkeley, California 94720, United States
- Materials Sciences Division, Lawrence Berkeley National Laboratory , Berkeley, California 94720, United States
| | - Christopher T Nelson
- Department of Materials Science and Engineering, University of California , Berkeley, California 94720, United States
- Materials Sciences Division, Lawrence Berkeley National Laboratory , Berkeley, California 94720, United States
| | - Jian-Jun Wang
- Department of Materials Science and Engineering, The Pennsylvania State University , University Park, Pennsylvania 16802, United States
| | - James F Scott
- Schools of Chemistry and Physics, University of St Andrews , St Andrews KY16 9ST, U.K
| | - Lane W Martin
- Department of Materials Science and Engineering, University of California , Berkeley, California 94720, United States
- Materials Sciences Division, Lawrence Berkeley National Laboratory , Berkeley, California 94720, United States
| | - Ramamoorthy Ramesh
- Department of Materials Science and Engineering, University of California , Berkeley, California 94720, United States
- Materials Sciences Division, Lawrence Berkeley National Laboratory , Berkeley, California 94720, United States
- Department of Physics, University of California , Berkeley, California 94720, United States
| | - Long-Qing Chen
- Department of Materials Science and Engineering, The Pennsylvania State University , University Park, Pennsylvania 16802, United States
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10
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Saremi S, Xu R, Dedon LR, Mundy JA, Hsu SL, Chen Z, Damodaran AR, Chapman SP, Evans JT, Martin LW. Enhanced Electrical Resistivity and Properties via Ion Bombardment of Ferroelectric Thin Films. Adv Mater 2016; 28:10750-10756. [PMID: 27723127 DOI: 10.1002/adma.201603968] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2016] [Revised: 09/01/2016] [Indexed: 06/06/2023]
Abstract
A novel approach to on-demand improvement of electronic properties in complex-oxide ferroelectrics is demonstrated whereby ion bombardment - commonly used in classic semiconductor materials - is applied to the PbTiO3 system. The result is deterministic reduction in leakage currents by 5 orders of magnitude, improved ferroelectric switching, and unprecedented insights into the nature of defects and intergap state evolution in these materials.
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Affiliation(s)
- Sahar Saremi
- Department of Materials Science and Engineering, University of California, Berkeley, Berkeley, CA, 94720, USA
| | - Ruijuan Xu
- Department of Materials Science and Engineering, University of California, Berkeley, Berkeley, CA, 94720, USA
| | - Liv R Dedon
- Department of Materials Science and Engineering, University of California, Berkeley, Berkeley, CA, 94720, USA
| | - Julia A Mundy
- Department of Materials Science and Engineering, University of California, Berkeley, Berkeley, CA, 94720, USA
- Materials Science Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Shang-Lin Hsu
- Department of Materials Science and Engineering, University of California, Berkeley, Berkeley, CA, 94720, USA
- Materials Science Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Zuhuang Chen
- Department of Materials Science and Engineering, University of California, Berkeley, Berkeley, CA, 94720, USA
- Materials Science Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Anoop R Damodaran
- Department of Materials Science and Engineering, University of California, Berkeley, Berkeley, CA, 94720, USA
| | - Scott P Chapman
- Radiant Technologies, Inc, 2835 Pan American Fwy., Ste. B/C, Albuquerque, NM, 87107, USA
| | - Joseph T Evans
- Radiant Technologies, Inc, 2835 Pan American Fwy., Ste. B/C, Albuquerque, NM, 87107, USA
| | - Lane W Martin
- Department of Materials Science and Engineering, University of California, Berkeley, Berkeley, CA, 94720, USA
- Materials Science Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
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11
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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. J Phys Condens Matter 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] [What about the content of this article? (0)] [Affiliation(s)] [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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12
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Yadav AK, Nelson CT, Hsu SL, Hong Z, Clarkson JD, Schlepütz CM, Damodaran AR, Shafer P, Arenholz E, Dedon LR, Chen D, Vishwanath A, Minor AM, Chen LQ, Scott JF, Martin LW, Ramesh R. Corrigendum: Observation of polar vortices in oxide superlattices. Nature 2016; 534:138. [PMID: 26934222 DOI: 10.1038/nature17420] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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13
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Pandya S, Damodaran AR, Xu R, Hsu SL, Agar JC, Martin LW. Strain-induced growth instability and nanoscale surface patterning in perovskite thin films. Sci Rep 2016; 6:26075. [PMID: 27194595 PMCID: PMC4872149 DOI: 10.1038/srep26075] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2015] [Accepted: 04/27/2016] [Indexed: 11/09/2022] Open
Abstract
Despite extensive studies on the effects of epitaxial strain on the evolution of the lattice and properties of materials, considerably less work has explored the impact of strain on growth dynamics. In this work, we demonstrate a growth-mode transition from 2D-step flow to self-organized, nanoscale 3D-island formation in PbZr0.2Ti0.8O3/SrRuO3/SrTiO3 (001) heterostructures as the kinetics of the growth process respond to the evolution of strain. With increasing heterostructure thickness and misfit dislocation formation at the buried interface, a periodic, modulated strain field is generated that alters the adatom binding energy and, in turn, leads to a kinetic instability that drives a transition from 2D growth to ordered, 3D-island formation. The results suggest that the periodically varying binding energy can lead to inhomogeneous adsorption kinetics causing preferential growth at certain sites. This, in conjunction with the presence of an Ehrlich-Schwoebel barrier, gives rise to long-range, periodically-ordered arrays of so-called "wedding cake" 3D nanostructures which self-assemble along the [100] and [010].
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Affiliation(s)
- Shishir Pandya
- Department of Materials Science and Engineering, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Anoop R Damodaran
- Department of Materials Science and Engineering, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Ruijuan Xu
- Department of Materials Science and Engineering, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Shang-Lin Hsu
- Department of Materials Science and Engineering, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Joshua C Agar
- Department of Materials Science and Engineering, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Lane W Martin
- Department of Materials Science and Engineering, University of California, Berkeley, Berkeley, CA 94720, USA.,Materials Science Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
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14
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Agar JC, Damodaran AR, Okatan MB, Kacher J, Gammer C, Vasudevan RK, Pandya S, Dedon LR, Mangalam RVK, Velarde GA, Jesse S, Balke N, Minor AM, Kalinin SV, Martin LW. Highly mobile ferroelastic domain walls in compositionally graded ferroelectric thin films. Nat Mater 2016; 15:549-556. [PMID: 26878312 DOI: 10.1038/nmat4567] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/21/2015] [Accepted: 01/18/2016] [Indexed: 06/05/2023]
Abstract
Domains and domain walls are critical in determining the response of ferroelectrics, and the ability to controllably create, annihilate, or move domains is essential to enable a range of next-generation devices. Whereas electric-field control has been demonstrated for ferroelectric 180° domain walls, similar control of ferroelastic domains has not been achieved. Here, using controlled composition and strain gradients, we demonstrate deterministic control of ferroelastic domains that are rendered highly mobile in a controlled and reversible manner. Through a combination of thin-film growth, transmission-electron-microscopy-based nanobeam diffraction and nanoscale band-excitation switching spectroscopy, we show that strain gradients in compositionally graded PbZr1-xTixO3 heterostructures stabilize needle-like ferroelastic domains that terminate inside the film. These needle-like domains are highly labile in the out-of-plane direction under applied electric fields, producing a locally enhanced piezoresponse. This work demonstrates the efficacy of novel modes of epitaxy in providing new modalities of domain engineering and potential for as-yet-unrealized nanoscale functional devices.
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Affiliation(s)
- J C Agar
- Department of Materials Science and Engineering, University of California, Berkeley, California 94720, USA
- Department of Materials Science and Engineering, University of Illinois, Urbana-Champaign, Urbana, Illinois 61801, USA
| | - A R Damodaran
- Department of Materials Science and Engineering, University of California, Berkeley, California 94720, USA
| | - M B Okatan
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - J Kacher
- Department of Materials Science and Engineering, University of California, Berkeley, California 94720, USA
- National Center for Electron Microscopy, Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - C Gammer
- Department of Materials Science and Engineering, University of California, Berkeley, California 94720, USA
- National Center for Electron Microscopy, Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - R K Vasudevan
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - S Pandya
- Department of Materials Science and Engineering, University of California, Berkeley, California 94720, USA
| | - L R Dedon
- Department of Materials Science and Engineering, University of California, Berkeley, California 94720, USA
| | - R V K Mangalam
- Department of Materials Science and Engineering, University of California, Berkeley, California 94720, USA
| | - G A Velarde
- Department of Materials Science and Engineering, University of Illinois, Urbana-Champaign, Urbana, Illinois 61801, USA
| | - S Jesse
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - N Balke
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - A M Minor
- Department of Materials Science and Engineering, University of California, Berkeley, California 94720, USA
- National Center for Electron Microscopy, Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - S V Kalinin
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - L W Martin
- Department of Materials Science and Engineering, University of California, Berkeley, California 94720, USA
- Materials Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
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15
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Jablonski ML, Liu S, Winkler CR, Damodaran AR, Grinberg I, Martin LW, Rappe AM, Taheri ML. Asymmetric Response of Ferroelastic Domain-Wall Motion under Applied Bias. ACS Appl Mater Interfaces 2016; 8:2935-2941. [PMID: 26695346 DOI: 10.1021/acsami.5b08312] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
The switching of domains in ferroelectric and multiferroic materials plays a central role in their application to next-generation computer systems, sensing applications, and memory storage. A detailed understanding of the response to electric fields and the switching behavior in the presence of complex domain structures and extrinsic effects (e.g., defects and dislocations) is crucial for the design of improved ferroelectrics. In this work, in situ transmission electron microscopy is coupled with atomistic molecular dynamics simulations to explore the response of 71° ferroelastic domain walls in BiFeO3 with various orientations under applied electric-field excitation. We observe that 71° domain walls can have intrinsically asymmetric responses to opposing biases. In particular, when the electric field has a component normal to the domain wall, forward and backward domain-wall velocities can be dramatically different for equal and opposite fields. Additionally, the presence of defects and dislocations can strongly affect the local switching behaviors through pinning or nucleation of the domain walls. These results offer insight for controlled ferroelastic domain manipulation via electric-field engineering.
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Affiliation(s)
- Michael L Jablonski
- Department of Materials Science and Engineering, Drexel University , Philadelphia, Pennsylvania 19104, United States
| | - Shi Liu
- Department of Chemistry, University of Pennsylvania , Philadelphia, Pennsylvania 19104, United States
- Geophysical Laboratory, Carnegie Institution for Science , Washington, D.C. 20015, United States
| | - Christopher R Winkler
- Department of Materials Science and Engineering, Drexel University , Philadelphia, Pennsylvania 19104, United States
| | - Anoop R Damodaran
- Department of Materials Science and Engineering, University of California, Berkeley , Berkeley, California 94720, United States
| | - Ilya Grinberg
- Department of Chemistry, University of Pennsylvania , Philadelphia, Pennsylvania 19104, United States
| | - Lane W Martin
- Department of Materials Science and Engineering, University of California, Berkeley , Berkeley, California 94720, United States
- Materials Science Division, Lawrence Berkeley National Laboratory , Berkeley, California 94720, United States
| | - Andrew M Rappe
- Department of Chemistry, University of Pennsylvania , Philadelphia, Pennsylvania 19104, United States
| | - Mitra L Taheri
- Department of Materials Science and Engineering, Drexel University , Philadelphia, Pennsylvania 19104, United States
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16
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Chen F, Goodfellow J, Liu S, Grinberg I, Hoffmann MC, Damodaran AR, Zhu Y, Zalden P, Zhang X, Takeuchi I, Rappe AM, Martin LW, Wen H, Lindenberg AM. Ultrafast Terahertz Gating of the Polarization and Giant Nonlinear Optical Response in BiFeO3 Thin Films. Adv Mater 2015; 27:6371-5. [PMID: 26389651 DOI: 10.1002/adma.201502975] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/2015] [Revised: 07/26/2015] [Indexed: 05/24/2023]
Abstract
Terahertz pulses are applied as an all-optical bias to ferroelectric thin-film BiFeO3 while monitoring the time-dependent ferroelectric polarization through its nonlinear optical response. Modulations in the intensity of the second harmonic light generated by the film correspond to on-off ratios of 220× gateable on femtosecond timescales. Polarization modulations comparable to the built-in static polarization are observed.
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Affiliation(s)
- Frank Chen
- SIMES Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, Menlo Park, CA, 94025, USA
- Department of Electrical Engineering, Stanford University, Stanford, CA, 94305, USA
| | - John Goodfellow
- SIMES Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, Menlo Park, CA, 94025, USA
- Department of Materials Science and Engineering, Stanford University, Stanford, CA, 94305, USA
| | - Shi Liu
- The Makineni Theoretical Laboratories, Department of Chemistry, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Ilya Grinberg
- The Makineni Theoretical Laboratories, Department of Chemistry, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | | | - Anoop R Damodaran
- Department of Materials Science and Engineering, University of California, Berkeley, CA, 94720, USA
| | - Yi Zhu
- Advanced Photon Source, Argonne National Laboratory, Lemont, IL, 60439, USA
| | - Peter Zalden
- SIMES Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, Menlo Park, CA, 94025, USA
| | - Xiaohang Zhang
- Department of Materials Science and Engineering, University of Maryland, College Park, MD, 20742, USA
| | - Ichiro Takeuchi
- Department of Materials Science and Engineering, University of Maryland, College Park, MD, 20742, USA
| | - Andrew M Rappe
- The Makineni Theoretical Laboratories, Department of Chemistry, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Lane W Martin
- Department of Materials Science and Engineering, University of California, Berkeley, CA, 94720, USA
- Materials Science Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Haidan Wen
- Advanced Photon Source, Argonne National Laboratory, Lemont, IL, 60439, USA
| | - Aaron M Lindenberg
- SIMES Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, Menlo Park, CA, 94025, USA
- Department of Materials Science and Engineering, Stanford University, Stanford, CA, 94305, USA
- PULSE Institute, SLAC National Accelerator Laboratory, Menlo Park, CA, 94025, USA
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17
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Chen Z, Liu J, Qi Y, Chen D, Hsu SL, Damodaran AR, He X, N'Diaye AT, Rockett A, Martin LW. 180° Ferroelectric Stripe Nanodomains in BiFeO3 Thin Films. Nano Lett 2015; 15:6506-6513. [PMID: 26317408 DOI: 10.1021/acs.nanolett.5b02031] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
There is growing evidence that domain walls in ferroics can possess emergent properties that are absent in the bulk. For example, 180° ferroelectric domain walls in the ferroelectric-antiferromagnetic BiFeO3 are particularly interesting because they have been predicted to possess a range of intriguing behaviors, including electronic conduction and enhanced magnetization. To date, however, ordered arrays of such domain structures have not been reported. Here, we report the observation of 180° stripe nanodomains in (110)-oriented BiFeO3 thin films grown on orthorhombic GdScO3 (010)O substrates and their impact on exchange coupling to metallic ferromagnets. Nanoscale ferroelectric 180° stripe domains with {112̅} domain walls were observed in films <32 nm thick. With increasing film thickness, we observed a domain structure crossover from the depolarization field-driven 180° stripe nanodomains to 71° ferroelastic domains determined by the elastic energy. These 180° domain walls (which are typically cylindrical or meandering in nature due to a lack of strong anisotropy associated with the energy of such walls) are found to be highly ordered. Additional studies of Co0.9Fe0.1/BiFeO3 heterostructures reveal exchange bias and exchange enhancement in heterostructures based on BiFeO3 with 180° domain walls and an absence of exchange bias in heterostructures based on BiFeO3 with 71° domain walls; suggesting that the 180° domain walls could be the possible source for pinned uncompensated spins that give rise to exchange bias. This is further confirmed by X-ray circular magnetic dichroism studies, which demonstrate that films with predominantly 180° domain walls have larger magnetization than those with primarily 71° domain walls. Our results could be useful to extract the structure of domain walls and to explore domain wall functionalities in BiFeO3.
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Affiliation(s)
| | | | - Yajun Qi
- Hubei Collaborative Innovation Centre for Advanced Organic Chemical Materials, Key Laboratory of Green Preparation and Application for Materials, Ministry of Education, Department of Materials Science and Engineering, Hubei University , Wuhan 430062, P. R. China
| | | | | | | | - Xiaoqing He
- Department of Materials Science and Engineering and Materials Research Laboratory, University of Illinois , Urbana-Champaign, Urbana, Illinois 61801, United States
| | | | - Angus Rockett
- Department of Materials Science and Engineering and Materials Research Laboratory, University of Illinois , Urbana-Champaign, Urbana, Illinois 61801, United States
- International Institute for Carbon Neutral Research, 744 Motooka, Nishi-ku, Fukuoka, 819-0395, Japan
| | - Lane W Martin
- International Institute for Carbon Neutral Research, 744 Motooka, Nishi-ku, Fukuoka, 819-0395, Japan
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18
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Agar JC, Damodaran AR, Velarde GA, Pandya S, Mangalam RVK, Martin LW. Complex Evolution of Built-in Potential in Compositionally-Graded PbZr(1-x)Ti(x)O3 Thin Films. ACS Nano 2015; 9:7332-7342. [PMID: 26125636 DOI: 10.1021/acsnano.5b02289] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Epitaxial strain has been widely used to tune crystal and domain structures in ferroelectric thin films. New avenues of strain engineering based on varying the composition at the nanometer scale have been shown to generate symmetry breaking and large strain gradients culminating in large built-in potentials. In this work, we develop routes to deterministically control these built-in potentials by exploiting the interplay between strain gradients, strain accommodation, and domain formation in compositionally graded PbZr1-xTixO3 heterostructures. We demonstrate that variations in the nature of the compositional gradient and heterostructure thickness can be used to control both the crystal and domain structures and give rise to nonintuitive evolution of the built-in potential, which does not scale directly with the magnitude of the strain gradient as would be expected. Instead, large built-in potentials are observed in compositionally-graded heterostructures that contain (1) compositional gradients that traverse chemistries associated with structural phase boundaries (such as the morphotropic phase boundary) and (2) ferroelastic domain structures. In turn, the built-in potential is observed to be dependent on a combination of flexoelectric effects (i.e., polarization-strain gradient coupling), chemical-gradient effects (i.e., polarization-chemical potential gradient coupling), and local inhomogeneities (in structure or chemistry) that enhance strain (and/or chemical potential) gradients such as areas with nonlinear lattice parameter variation with chemistry or near ferroelastic domain boundaries. Regardless of origin, large built-in potentials act to suppress the dielectric permittivity, while having minimal impact on the magnitude of the polarization, which is important for the optimization of these materials for a range of nanoapplications from vibrational energy harvesting to thermal energy conversion and beyond.
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Affiliation(s)
- Joshua C Agar
- †Department of Materials Science and Engineering, University of California, Berkeley, Berkeley, California 94720, United States
- ‡Department of Materials Science and Engineering, University of Illinois, Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Anoop R Damodaran
- †Department of Materials Science and Engineering, University of California, Berkeley, Berkeley, California 94720, United States
| | - Gabriel A Velarde
- ‡Department of Materials Science and Engineering, University of Illinois, Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Shishir Pandya
- †Department of Materials Science and Engineering, University of California, Berkeley, Berkeley, California 94720, United States
| | - R V K Mangalam
- †Department of Materials Science and Engineering, University of California, Berkeley, Berkeley, California 94720, United States
| | - Lane W Martin
- †Department of Materials Science and Engineering, University of California, Berkeley, Berkeley, California 94720, United States
- ‡Department of Materials Science and Engineering, University of Illinois, Urbana-Champaign, Urbana, Illinois 61801, United States
- §Materials Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
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19
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Spurgeon SR, Balachandran PV, Kepaptsoglou DM, Damodaran AR, Karthik J, Nejati S, Jones L, Ambaye H, Lauter V, Ramasse QM, Lau KKS, Martin LW, Rondinelli JM, Taheri ML. Polarization screening-induced magnetic phase gradients at complex oxide interfaces. Nat Commun 2015; 6:6735. [DOI: 10.1038/ncomms7735] [Citation(s) in RCA: 67] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2014] [Accepted: 02/20/2015] [Indexed: 01/07/2023] Open
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20
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Lee S, Damodaran AR, Gorai P, Oh N, Moyer JA, Kwon JH, Ferdous N, Shah A, Chen Z, Breckenfeld E, Mangalam RVK, Braun PV, Schiffer P, Shim M, Zuo JM, Ertekin E, Martin LW. A novel, layered phase in Ti-rich SrTiO3 epitaxial thin films. Adv Mater 2015; 27:861-868. [PMID: 25523179 DOI: 10.1002/adma.201403602] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2014] [Revised: 10/20/2014] [Indexed: 06/04/2023]
Abstract
Sr2Ti7O14, a new phase, is synthesized by leveraging the innate chemical and thermo-dynamic instabilities in the SrTiO3-TiO2 system and non-equilibrium growth techniques. The chemical composition, epitaxial relationships, and orientation play roles in the formation of this novel layered phase, which, in turn, possesses unusual charge ordering, anti-ferromagnetic ordering, and low, glass-like thermal conductivity.
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Affiliation(s)
- Sungki Lee
- Department of Materials Science and Engineering, University of California Berkeley, Berkeley, California, 94720, USA
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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. Nat Mater 2015; 14:79-86. [PMID: 25344784 DOI: 10.1038/nmat4119] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [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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22
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Breckenfeld E, Chen Z, Damodaran AR, Martin LW. Effects of nonequilibrium growth, nonstoichiometry, and film orientation on the metal-to-insulator transition in NdNiO₃ thin films. ACS Appl Mater Interfaces 2014; 6:22436-44. [PMID: 25454898 DOI: 10.1021/am506436s] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Next-generation devices will rely on exotic functional properties not found in traditional systems. One class of materials of particular interest for applications are those possessing metal-to-insulator transitions (MITs). In this work, we probe the relationship between variations in the growth process, subsequent variations in cation stoichiometry, and the MIT in NdNiO3 thin films. Slight variations in the growth conditions, in particular the laser fluence, during pulsed-laser deposition growth of NdNiO3 produces films that are both single-phase and coherently strained to a range of substrates despite possessing as much as 15% Nd-excess. Subsequent study of the temperature-dependence of the electronic transport reveals dramatic changes in both the onset and magnitude of the resistivity change at the MIT with increasing cation nonstoichiometry giving rise to a decrease (and ultimately a suppression) of the transition and the magnitude of the resistivity change. From there, the electronic transport of nearly ideal NdNiO3 thin films are studied as a function of epitaxial strain, thickness, and orientation. Overall, transitioning from tensile to compressive strain results in a systematic reduction of the onset and magnitude of the resistivity change across the MIT, thinner films are found to possess sharper MITs with larger changes in the resistivity at the transition, and (001)-oriented films exhibit sharper and larger MITs as compared to (110)- and (111)-oriented films as a result of highly anisotropic in-plane transport in the latter.
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Affiliation(s)
- Eric Breckenfeld
- Materials Science and Technology Division, Code 6364, Naval Research Laboratory , Washington, DC 20475, United States
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23
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Damodaran AR, Breckenfeld E, Chen Z, Lee S, Martin LW. Enhancement of ferroelectric Curie temperature in BaTiO3 films via strain-induced defect dipole alignment. Adv Mater 2014; 26:6341-6347. [PMID: 25099557 DOI: 10.1002/adma.201400254] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/16/2014] [Revised: 06/18/2014] [Indexed: 06/03/2023]
Abstract
The combination of epitaxial strain and defect engineering facilitates the tuning of the transition temperature of BaTiO3 to >800 °C. Advances in thin-film deposition enable the utilization of both the electric and elastic dipoles of defects to extend the epitaxial strain to new levels, inducing unprecedented functionality and temperature stability in ferroelectrics.
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Affiliation(s)
- Anoop R Damodaran
- Department of Materials Science and Engineering and Materials Research Laboratory, University of Illinois, Urbana-Champaign, Urbana, IL, 61801, USA; Department of Materials Science and Engineering, University of California, Berkeley, Berkeley, CA, 94720, USA
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24
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Winkler CR, Jablonski ML, Ashraf K, Damodaran AR, Jambunathan K, Hart JL, Wen JG, Miller DJ, Martin LW, Salahuddin S, Taheri ML. Real-time observation of local strain effects on nonvolatile ferroelectric memory storage mechanisms. Nano Lett 2014; 14:3617-3622. [PMID: 24801618 DOI: 10.1021/nl501304e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
We use in situ transmission electron microscopy to directly observe, at high temporal and spatial resolution, the interaction of ferroelectric domains and dislocation networks within BiFeO3 thin films. The experimental observations are compared with a phase field model constructed to simulate the dynamics of domains in the presence of dislocations and their resulting strain fields. We demonstrate that a global network of misfit dislocations at the film-substrate interface can act as nucleation sites and slow down domain propagation in the vicinity of the dislocations. Networks of individual threading dislocations emanating from the film-electrode interface play a more dramatic role in pinning domain motion. These dislocations may be responsible for the domain behavior in ferroelectric thin-film devices deviating from conventional Kolmogorov-Avrami-Ishibashi dynamics toward a Nucleation Limited Switching model.
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Affiliation(s)
- Christopher R Winkler
- Department of Materials Science & Engineering, Drexel University , Philadelphia, Pennsylvania 19104, United States
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25
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Spurgeon SR, Sloppy JD, Kepaptsoglou DMD, Balachandran PV, Nejati S, Karthik J, Damodaran AR, Johnson CL, Ambaye H, Goyette R, Lauter V, Ramasse QM, Idrobo JC, Lau KKS, Lofland SE, Rondinelli JM, Martin LW, Taheri ML. Thickness-dependent crossover from charge- to strain-mediated magnetoelectric coupling in ferromagnetic/piezoelectric oxide heterostructures. ACS Nano 2014; 8:894-903. [PMID: 24313563 DOI: 10.1021/nn405636c] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Magnetoelectric oxide heterostructures are proposed active layers for spintronic memory and logic devices, where information is conveyed through spin transport in the solid state. Incomplete theories of the coupling between local strain, charge, and magnetic order have limited their deployment into new information and communication technologies. In this study, we report direct, local measurements of strain- and charge-mediated magnetization changes in the La0.7Sr0.3MnO3/PbZr0.2Ti0.8O3 system using spatially resolved characterization techniques in both real and reciprocal space. Polarized neutron reflectometry reveals a graded magnetization that results from both local structural distortions and interfacial screening of bound surface charge from the adjacent ferroelectric. Density functional theory calculations support the experimental observation that strain locally suppresses the magnetization through a change in the Mn-eg orbital polarization. We suggest that this local coupling and magnetization suppression may be tuned by controlling the manganite and ferroelectric layer thicknesses, with direct implications for device applications.
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Affiliation(s)
- Steven R Spurgeon
- Department of Materials Science and Engineering, Drexel University , Philadelphia, Pennsylvania, United States
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26
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Xu R, Karthik J, Damodaran AR, Martin LW. Stationary domain wall contribution to enhanced ferroelectric susceptibility. Nat Commun 2014; 5:3120. [DOI: 10.1038/ncomms4120] [Citation(s) in RCA: 78] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2013] [Accepted: 12/16/2013] [Indexed: 11/09/2022] Open
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27
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Mangalam RVK, Agar JC, Damodaran AR, Karthik J, Martin LW. Improved pyroelectric figures of merit in compositionally graded PbZr1-xTixO3 thin films. ACS Appl Mater Interfaces 2013; 5:13235-13241. [PMID: 24299171 DOI: 10.1021/am404228c] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Pyroelectric materials have been widely used for a range of thermal-related applications including thermal imaging/sensing, waste heat energy conversion, and electron emission. In general, the figures of merit for applications of pyroelectric materials are proportional to the pyroelectric coefficient and inversely proportional to the dielectric permittivity. In this context, we explore single-layer and compositionally graded PbZr1-xTixO3 thin-film heterostructures as a way to independently engineer the pyroelectric coefficient and dielectric permittivity of materials and increase overall performance. Compositional gradients in thin films are found to produce large strain gradients which generate large built-in potentials in the films that can reduce the permittivity while maintaining large pyroelectric response. Routes to enhance the figures of merit of pyroelectric materials by 3-12 times are reported, and comparisons to standard materials are made.
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Affiliation(s)
- R V K Mangalam
- Department of Materials Science and Engineering and Materials Research Laboratory, University of Illinois, Urbana-Champaign , Urbana, Illinois 61801, United States
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28
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Breckenfeld E, Bronn N, Karthik J, Damodaran AR, Lee S, Mason N, Martin LW. Effect of growth induced (non)stoichiometry on interfacial conductance in LaAlO3/SrTiO3. Phys Rev Lett 2013; 110:196804. [PMID: 23705735 DOI: 10.1103/physrevlett.110.196804] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/29/2012] [Indexed: 06/02/2023]
Abstract
We demonstrate a link between the growth process, the stoichiometry of LaAlO(3), and the interfacial electrical properties of LaAlO(3)/SrTiO(3) heterointerfaces. Varying the relative La:Al cation stoichiometry by a few atomic percent in films grown at 1×10(-3) Torr results in a 2 and 7 order-of-magnitude change in the 300 and 2 K sheet resistance, respectively, with highly conducting states occurring only in La-deficient or Al-excess films. Further reducing the growth pressure results in an increase of the carrier density and a dramatic change in mobility. We discuss the relative contributions of intrinsic and extrinsic effects in controlling the physical properties of this widely studied system.
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Affiliation(s)
- E Breckenfeld
- Department of Materials Science and Engineering and Materials Research Laboratory, University of Illinois, Urbana-Champaign, Urbana, Illinois 61801, USA
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29
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Mangalam RVK, Karthik J, Damodaran AR, Agar JC, Martin LW. Unexpected crystal and domain structures and properties in compositionally graded PbZr(1-x)Ti(x)O3 thin films. Adv Mater 2013; 25:1761-7. [PMID: 23359407 DOI: 10.1002/adma.201204240] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2012] [Revised: 11/25/2012] [Indexed: 05/10/2023]
Abstract
Synthesis of compositionally graded versions of PbZr(1-x)Ti(x)O3 thin films results in unprecedented strains (as large as ≈4.5 × 10(5) m(-1)) and correspondingly unexpected crystal structures, ferroelectric domain structures, and properties. This includes the observation of built-in electric fields in films as large as 200 kV/cm. Compositional and strain gradients could represent a new direction of strain-control of materials.
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Affiliation(s)
- R V K Mangalam
- Department of Materials Science and Engineering and Materials Research Laboratory, University of Illinois, Urbana-Champaign, Urbana, IL 61801, USA
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30
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Karthik J, Agar JC, Damodaran AR, Martin LW. Effect of 90° domain walls and thermal expansion mismatch on the pyroelectric properties of epitaxial PbZr0.2Ti0.8O3 thin films. Phys Rev Lett 2012; 109:257602. [PMID: 23368500 DOI: 10.1103/physrevlett.109.257602] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/07/2012] [Indexed: 06/01/2023]
Abstract
We have investigated the contribution of 90° domain walls and thermal expansion mismatch to pyroelectricity in PbZr(0.2)Ti(0.8)O(3) thin films. The first phenomenological models to include extrinsic and secondary contributions to pyroelectricity in polydomain films predict significant extrinsic contributions (arising from the temperature-dependent motion of domain walls) and large secondary contributions (arising from thermal expansion mismatch between the film and the substrate). Phase-sensitive pyroelectric current measurements are applied to model thin films for the first time and reveal a dramatic increase in the pyroelectric coefficient with increasing fraction of in-plane oriented domains and thermal expansion mismatch.
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Affiliation(s)
- J Karthik
- Department of Materials Science and Engineering and Materials Research Laboratory, University of Illinois, Urbana-Champaign, Urbana, Illinois 61801, USA
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31
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Jackson R, Fletcher PC, Jambunathan K, Damodaran AR, Emmerich JN, Teng H, Martin LW, King WP, Wu Y. Note: electrical and thermal characterization of a ferroelectric thin film with an electro-thermal nanoprobe. Rev Sci Instrum 2012; 83:076105. [PMID: 22852740 DOI: 10.1063/1.4733730] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
The localized temperature-dependent piezoelectric response of ferroelectric barium strontium titanate (BST) thin films is studied using an electro-thermal (ET) nanoprobe. The ET probe provides independent electrical and thermal excitation to a nanometer-scale volume of the specimen and is capable of detecting the phase transition temperature of the BST thin films. The piezoresponse measured by the ET probe follows the temperature dependence of the piezoelectric constant, whereas with bulk heating the response follows the temperature dependence of the spontaneous polarization. The observed differences stem from the localized inhomogeneous electro-thermal field distribution at the specimen.
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Affiliation(s)
- R Jackson
- College of Engineering, Mathematics, and Science, University of Wisconsin-Platteville, Platteville, Wisconsin 53818, USA
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32
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Polisetty S, Zhou J, Karthik J, Damodaran AR, Chen D, Scholl A, Martin LW, Holcomb M. X-ray linear dichroism dependence on ferroelectric polarization. J Phys Condens Matter 2012; 24:245902. [PMID: 22627181 DOI: 10.1088/0953-8984/24/24/245902] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
X-ray absorption spectroscopy and photoemission electron microscopy are techniques commonly used to determine the magnetic properties of thin films, crystals, and heterostructures. Recently, these methods have been used in the study of magnetoelectrics and multiferroics. The analysis of such materials has been compromised by the presence of multiple order parameters and the lack of information on how to separate these coupled properties. In this work, we shed light on the manifestation of dichroism from ferroelectric polarization and atomic structure using photoemission electron microscopy and x-ray absorption spectroscopy. Linear dichroism arising from the ferroelectric order in the PbZr0:2Ti0:8O3 thin films was studied as a function of incident x-ray polarization and geometry to unambiguously determine the angular dependence of the ferroelectric contribution to the dichroism. These measurements allow us to examine the contribution of surface charges and ferroelectric polarization as potential mechanisms for linear dichroism. The x-ray linear dichroism from ferroelectric order revealed an angular dependence based on the angle between the ferroelectric polarization direction and the x-ray polarization axis, allowing a formula for linear dichroism in ferroelectric samples to be defined.
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Affiliation(s)
- S Polisetty
- Department of Physics, West Virginia University, Morgantown, WV 26506, USA.
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33
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Karthik J, Damodaran AR, Martin LW. Effect of 90° domain walls on the low-field permittivity of PbZr(0.2)Ti(0.8)O3 thin films. Phys Rev Lett 2012; 108:167601. [PMID: 22680755 DOI: 10.1103/physrevlett.108.167601] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/26/2011] [Revised: 01/19/2012] [Indexed: 06/01/2023]
Abstract
We report on the contribution of 90° ferroelastic domain walls in strain-engineered PbZr(0.2)Ti(0.8)O(3) thin films to the room-temperature permittivity. Using a combination of phenomenological Ginzburg-Landau-Devonshire polydomain thin-film models and epitaxial thin-film growth and characterization, the extrinsic or domain wall contribution to the low-field, reversible dielectric response is evaluated as a function of increasing domain wall density. Using epitaxial thin-film strain we have engineered a set of samples that possess a known quantity of 90° domain walls that act as a model system with which to probe the contribution from these ferroelastic domain walls. We observe a strong enhancement of the permittivity with increasing domain wall density that matches the predictions of the phenomenological models. Additionally, we report experimentally measured bounds to domain wall stiffness in such PbZr(0.2)Ti(0.8)O(3) thin films as a function of domain wall density and frequency.
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Affiliation(s)
- J Karthik
- Department of Materials Science and Engineering and Materials Research Laboratory, University of Illinois, Urbana-Champaign, Urbana, Illinois 61801, USA
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Karthik J, Damodaran AR, Martin LW. Epitaxial ferroelectric heterostructures fabricated by selective area epitaxy of SrRuO3 using an MgO mask. Adv Mater 2012; 24:1610-1615. [PMID: 22354578 DOI: 10.1002/adma.201104697] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2011] [Revised: 01/22/2012] [Indexed: 05/31/2023]
Abstract
Illustration of a new high-temperature hard-mask process based on traditional lithography and selective wet-etching of MgO. The hard mask is compatible with standard nano-lithography techniques and heat treatments in excess of 1000 °C. Here, this technique is applied to produce temperature-stable contacts that give rise to low leakage, improved fatigue properties, and excellent high-temperature stability in ferroelectric thin-film capacitors.
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Affiliation(s)
- J Karthik
- Department of Materials Science and Engineering and Materials Research Laboratory, University of Illinois, Urbana-Champaign, Urbana, IL 61801, USA
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35
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Damodaran AR, Liang CW, He Q, Peng CY, Chang L, Chu YH, Martin LW. Nanoscale structure and mechanism for enhanced electromechanical response of highly Strained BiFeO3 thin films. Adv Mater 2011; 23:3170-3175. [PMID: 21608053 DOI: 10.1002/adma.201101164] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2011] [Indexed: 05/30/2023]
Affiliation(s)
- Anoop R Damodaran
- Department of Materials Science and Engineering, F. Seitz Materials Research Laboratory, University of Illinois Urbana-Champaign, Urbana, IL 61801, USA.
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