1
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Dwij V, De B, Kunwar HS, Rana S, Velpula P, Shukla DK, Gupta MK, Mittal R, Pal S, Briscoe J, Sathe VG. Optical Control of In-Plane Domain Configuration and Domain Wall Motion in Ferroelectric and Ferroelastic Materials. ACS APPLIED MATERIALS & INTERFACES 2024; 16:33752-33762. [PMID: 38902888 DOI: 10.1021/acsami.4c02901] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/22/2024]
Abstract
The sensitivity of ferroelectric domain walls to external stimuli makes them functional entities in nanoelectronic devices. Specifically, optically driven domain reconfiguration with in-plane polarization is advantageous and thus is highly sought. Here, we show the existence of in-plane polarized subdomains imitating a single domain state and reversible optical control of its domain wall movement in a single-crystal of ferroelectric BaTiO3. Similar optical control in the domain configuration of nonpolar ferroelastic material indicates that long-range ferroelectric polarization is not essential for the optical control of domain wall movement. Instead, flexoelectricity is found to be an essential ingredient for the optical control of the domain configuration, and hence, ferroelastic materials would be another possible candidate for nanoelectronic device applications.
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Affiliation(s)
- Vivek Dwij
- UGC-DAE Consortium for Scientific Research, Indore 452001, India
| | - Binoy De
- UGC-DAE Consortium for Scientific Research, Indore 452001, India
| | | | - Sumesh Rana
- UGC-DAE Consortium for Scientific Research, Indore 452001, India
| | - Praveen Velpula
- UGC-DAE Consortium for Scientific Research, Indore 452001, India
| | - Dinesh K Shukla
- UGC-DAE Consortium for Scientific Research, Indore 452001, India
| | - Mayanak Kumar Gupta
- Solid State Physics Division, Bhabha Atomic Research Center, Mumbai 400 085, India
- Homi Bhabha National Institute, Anushaktinagar, Mumbai 400094, India
| | - Ranjan Mittal
- Solid State Physics Division, Bhabha Atomic Research Center, Mumbai 400 085, India
- Homi Bhabha National Institute, Anushaktinagar, Mumbai 400094, India
| | - Subhajit Pal
- School of Engineering & Materials Science, Queen Mary University of London, London E1 4NS, United Kingdom
| | - Joe Briscoe
- School of Engineering & Materials Science, Queen Mary University of London, London E1 4NS, United Kingdom
| | - Vasant G Sathe
- UGC-DAE Consortium for Scientific Research, Indore 452001, India
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2
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Olaniyan II, Schmitt SW, Albert J, Garcia Fernandez J, Marcelot C, Cours R, Deshpande V, Cherkashin N, Schamm-Chardon S, Kim DJ, Dubourdieu C. Shaping single crystalline BaTiO 3nanostructures by focused neon or helium ion milling. NANOTECHNOLOGY 2024; 35:335301. [PMID: 38701774 DOI: 10.1088/1361-6528/ad4713] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2024] [Accepted: 05/03/2024] [Indexed: 05/05/2024]
Abstract
The realization of perovskite oxide nanostructures with controlled shape and dimensions remains a challenge. Here, we investigate the use of helium and neon focused ion beam (FIB) milling in an ion microscope to fabricate BaTiO3nanopillars of sub-500 nm in diameter starting from BaTiO3(001) single crystals. Irradiation of BaTiO3with He ions induces the formation of nanobubbles inside the material, eventually leading to surface swelling and blistering. Ne-FIB is shown to be suitable for milling without inducing surface swelling. The resulting structures are defect-free single crystal nanopillars, which are enveloped, on the top and lateral sidewalls, by a point defect-rich crystalline region and an outer Ne-rich amorphous layer. The amorphous layer can be selectively etched by dipping in diluted HF. The geometry and beam-induced damage of the milled nanopillars depend strongly on the patterning parameters and can be well controlled. Ne ion milling is shown to be an effective method to rapidly prototype BaTiO3crystalline nanostructures.
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Affiliation(s)
- I I Olaniyan
- Helmholtz-Zentrum Berlin für Materialien und Energie, Hahn-Meitner Platz 1, D-14109 Berlin, Germany
- Freie Universität Berlin, Physical and Theoretical Chemistry, Arnimallee 22, D-14195 Berlin, Germany
| | - S W Schmitt
- Helmholtz-Zentrum Berlin für Materialien und Energie, Hahn-Meitner Platz 1, D-14109 Berlin, Germany
| | - J Albert
- Helmholtz-Zentrum Berlin für Materialien und Energie, Hahn-Meitner Platz 1, D-14109 Berlin, Germany
| | - J Garcia Fernandez
- CEMES-CNRS and Université de Toulouse, 29 rue Jeanne Marvig, F-31055 Toulouse, France
| | - C Marcelot
- CEMES-CNRS and Université de Toulouse, 29 rue Jeanne Marvig, F-31055 Toulouse, France
| | - R Cours
- CEMES-CNRS and Université de Toulouse, 29 rue Jeanne Marvig, F-31055 Toulouse, France
| | - V Deshpande
- Helmholtz-Zentrum Berlin für Materialien und Energie, Hahn-Meitner Platz 1, D-14109 Berlin, Germany
| | - N Cherkashin
- CEMES-CNRS and Université de Toulouse, 29 rue Jeanne Marvig, F-31055 Toulouse, France
| | - S Schamm-Chardon
- CEMES-CNRS and Université de Toulouse, 29 rue Jeanne Marvig, F-31055 Toulouse, France
| | - D J Kim
- Helmholtz-Zentrum Berlin für Materialien und Energie, Hahn-Meitner Platz 1, D-14109 Berlin, Germany
| | - C Dubourdieu
- Helmholtz-Zentrum Berlin für Materialien und Energie, Hahn-Meitner Platz 1, D-14109 Berlin, Germany
- Freie Universität Berlin, Physical and Theoretical Chemistry, Arnimallee 22, D-14195 Berlin, Germany
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3
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Gradauskaite E, Meier QN, Gray N, Sarott MF, Scharsach T, Campanini M, Moran T, Vogel A, Del Cid-Ledezma K, Huey BD, Rossell MD, Fiebig M, Trassin M. Defeating depolarizing fields with artificial flux closure in ultrathin ferroelectrics. NATURE MATERIALS 2023; 22:1492-1498. [PMID: 37783942 PMCID: PMC10713449 DOI: 10.1038/s41563-023-01674-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Accepted: 08/25/2023] [Indexed: 10/04/2023]
Abstract
Material surfaces encompass structural and chemical discontinuities that often lead to the loss of the property of interest in so-called dead layers. It is particularly problematic in nanoscale oxide electronics, where the integration of strongly correlated materials into devices is obstructed by the thickness threshold required for the emergence of their functionality. Here we report the stabilization of ultrathin out-of-plane ferroelectricity in oxide heterostructures through the design of an artificial flux-closure architecture. Inserting an in-plane-polarized ferroelectric epitaxial buffer provides the continuity of polarization at the interface; despite its insulating nature, we observe the emergence of polarization in our out-of-plane-polarized model of ferroelectric BaTiO3 from the very first unit cell. In BiFeO3, the flux-closure approach stabilizes a 251° domain wall. Its unusual chirality is probably associated with the ferroelectric analogue to the Dzyaloshinskii-Moriya interaction. We, thus, see that in an adaptively engineered geometry, the depolarizing-field-screening properties of an insulator can even surpass those of a metal and be a source of functionality. This could be a useful insight on the road towards the next generation of oxide electronics.
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Affiliation(s)
| | | | - Natascha Gray
- Department of Materials, ETH Zurich, Zurich, Switzerland
| | | | | | | | - Thomas Moran
- Department of Materials Science and Engineering, University of Connecticut, Storrs, CT, USA
| | | | - Karla Del Cid-Ledezma
- Department of Materials Science and Engineering, University of Connecticut, Storrs, CT, USA
| | - Bryan D Huey
- Department of Materials Science and Engineering, University of Connecticut, Storrs, CT, USA
| | | | - Manfred Fiebig
- Department of Materials, ETH Zurich, Zurich, Switzerland
| | - Morgan Trassin
- Department of Materials, ETH Zurich, Zurich, Switzerland.
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4
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Domingo N. Bowing to ferroelectric artificial flux closure. NATURE MATERIALS 2023:10.1038/s41563-023-01714-x. [PMID: 38017042 DOI: 10.1038/s41563-023-01714-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/30/2023]
Affiliation(s)
- Neus Domingo
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN, USA.
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5
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Noheda B, Nukala P, Acuautla M. Lessons from hafnium dioxide-based ferroelectrics. NATURE MATERIALS 2023; 22:562-569. [PMID: 37138006 DOI: 10.1038/s41563-023-01507-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2022] [Accepted: 02/13/2023] [Indexed: 05/05/2023]
Abstract
A bit more than a decade after the first report of ferroelectric switching in hafnium dioxide-based ultrathin layers, this family of materials continues to elicit interest. There is ample consensus that the observed switching does not obey the same mechanisms present in most other ferroelectrics, but its exact nature is still under debate. Next to this fundamental relevance, a large research effort is dedicated to optimizing the use of this extraordinary material, which already shows direct integrability in current semiconductor chips and potential for scalability to the smallest node architectures, in smaller and more reliable devices. Here we present a perspective on how, despite our incomplete understanding and remaining device endurance issues, the lessons learned from hafnium dioxide-based ferroelectrics offer interesting avenues beyond ferroelectric random-access memories and field-effect transistors. We hope that research along these other directions will stimulate discoveries that, in turn, will mitigate some of the current issues. Extending the scope of available systems will eventually enable the way to low-power electronics, self-powered devices and energy-efficient information processing.
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Affiliation(s)
- Beatriz Noheda
- Zernike Institute for Advanced Materials, University of Groningen, Groningen, The Netherlands.
- CogniGron Center, University of Groningen, Groningen, The Netherlands.
| | - Pavan Nukala
- Center for Nanoscience and Engineering, Indian Institute of Science, Bengaluru, India
| | - Mónica Acuautla
- Engineering and Technology Institute Groningen (ENTEG), University of Groningen, Groningen, The Netherlands
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6
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Buragohain P, Lu H, Richter C, Schenk T, Kariuki P, Glinsek S, Funakubo H, Íñiguez J, Defay E, Schroeder U, Gruverman A. Quantification of the Electromechanical Measurements by Piezoresponse Force Microscopy. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2022; 34:e2206237. [PMID: 36210741 DOI: 10.1002/adma.202206237] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/09/2022] [Revised: 09/10/2022] [Indexed: 06/16/2023]
Abstract
Piezoresponse force microscopy (PFM) is widely used for characterization and exploration of the nanoscale properties of ferroelectrics. However, quantification of the PFM signal is challenging due to the convolution of various extrinsic and intrinsic contributions. Although quantification of the PFM amplitude signal has received considerable attention, quantification of the PFM phase signal has not been addressed. A properly calibrated PFM phase signal can provide valuable information on the sign of the local piezoelectric coefficient-an important and nontrivial issue for emerging ferroelectrics. In this work, two complementary methodologies to calibrate the PFM phase signal are discussed. The first approach is based on using a standard reference sample with well-known independently measured piezoelectric coefficients, while the second approach exploits the electrostatic sample-cantilever interactions to determine the parasitic phase offset. Application of these methodologies to studies of the piezoelectric behavior in ferroelectric HfO2 -based thin-film capacitors reveals intriguing variations in the sign of the longitudinal piezoelectric coefficient, d33,eff . It is shown that the piezoelectric properties of the HfO2 -based capacitors are inherently sensitive to their thickness, electrodes, as well as deposition methods, and can exhibit wide variations including a d33,eff sign change within a single device.
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Affiliation(s)
- Pratyush Buragohain
- Department of Physics and Astronomy, University of Nebraska-Lincoln, Lincoln, NE 68588, USA
| | - Haidong Lu
- Department of Physics and Astronomy, University of Nebraska-Lincoln, Lincoln, NE 68588, USA
| | - Claudia Richter
- NaMLab gGmbH, 01187, Noethnitzer Strasse 64 a, Dresden, Germany
| | - Tony Schenk
- Ferroelectric Memory GmbH, 01099, Charlotte-Bühler-Str. 12, Dresden, Germany
| | - Pamenas Kariuki
- NaMLab gGmbH, 01187, Noethnitzer Strasse 64 a, Dresden, Germany
| | - Sebastjan Glinsek
- Materials Research and Technology Department, Luxembourg Institute of Science and Technology, 41 Rue du Brill, Belvaux, L-4422, Luxembourg
| | - Hiroshi Funakubo
- School of Materials and Chemical Technology, Tokyo Institute of Technology, Yokohama, 226-8502, Japan
| | - Jorge Íñiguez
- Materials Research and Technology Department, Luxembourg Institute of Science and Technology, 41 Rue du Brill, Belvaux, L-4422, Luxembourg
- Department of Physics and Materials Science, University of Luxembourg, 41 Rue du Brill, Belvaux, L-4422, Luxembourg
| | - Emmanuel Defay
- Materials Research and Technology Department, Luxembourg Institute of Science and Technology, 41 Rue du Brill, Belvaux, L-4422, Luxembourg
| | - Uwe Schroeder
- NaMLab gGmbH, 01187, Noethnitzer Strasse 64 a, Dresden, Germany
| | - Alexei Gruverman
- Department of Physics and Astronomy, University of Nebraska-Lincoln, Lincoln, NE 68588, USA
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7
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Tikhonov Y, Maguire JR, McCluskey CJ, McConville JPV, Kumar A, Lu H, Meier D, Razumnaya A, Gregg JM, Gruverman A, Vinokur VM, Luk'yanchuk I. Polarization Topology at the Nominally Charged Domain Walls in Uniaxial Ferroelectrics. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2022; 34:e2203028. [PMID: 36114716 DOI: 10.1002/adma.202203028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2022] [Revised: 09/06/2022] [Indexed: 06/15/2023]
Abstract
Ferroelectric domain walls provide a fertile environment for novel materials physics. If a polarization discontinuity arises, it can drive a redistribution of electronic carriers and changes in band structure, which often result in emergent 2D conductivity. If such a discontinuity is not tolerated, then its amelioration usually involves the formation of complex topological patterns, such as flux-closure domains, dipolar vortices, skyrmions, merons, or Hopfions. The degrees of freedom required for the development of such patterns, in which dipolar rotation is a hallmark, are readily found in multiaxial ferroelectrics. In uniaxial ferroelectrics, where only two opposite polar orientations are possible, it has been assumed that discontinuities are unavoidable when antiparallel components of polarization meet. This perception has been borne out by the appearance of charged conducting domain walls in systems such as hexagonal manganites and lithium niobate. Here, experimental and theoretical investigations on lead germanate (Pb5 Ge3 O11 ) reveal that polar discontinuities can be obviated at head-to-head and tail-to-tail domain walls by mutual domain bifurcation along two different axes, creating a characteristic saddle-point domain wall morphology and associated novel dipolar topology, removing the need for screening charge accumulation and associated conductivity enhancement.
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Affiliation(s)
- Yurii Tikhonov
- University of Picardie, Laboratory of Condensed Matter Physics, Amiens, 80039, France
- Faculty of Physics, Southern Federal University, 5 Zorge Street, Rostov-on-Don, 344090, Russia
| | - Jesi R Maguire
- Centre for Nanostructured Media, School of Mathematics and Physics, Queen's University Belfast, Belfast, BT7 1NN, UK
| | - Conor J McCluskey
- Centre for Nanostructured Media, School of Mathematics and Physics, Queen's University Belfast, Belfast, BT7 1NN, UK
| | - James P V McConville
- Centre for Nanostructured Media, School of Mathematics and Physics, Queen's University Belfast, Belfast, BT7 1NN, UK
| | - Amit Kumar
- Centre for Nanostructured Media, School of Mathematics and Physics, Queen's University Belfast, Belfast, BT7 1NN, UK
| | - Haidong Lu
- Department of Physics and Astronomy, University of Nebraska-Lincoln, Lincoln, NE, 68588, USA
| | - Dennis Meier
- Department of Materials Science and Engineering, Norwegian University of Science and Technology (NTNU), Trondheim, 7491, Norway
| | - Anna Razumnaya
- Jožef Stefan Institute, Jamova Cesta 39, Ljubljana, 1000, Slovenia
- Terra Quantum AG, Kornhausstrasse 25, St. Gallen, CH-9000, Switzerland
| | - John Martin Gregg
- Centre for Nanostructured Media, School of Mathematics and Physics, Queen's University Belfast, Belfast, BT7 1NN, UK
| | - Alexei Gruverman
- Department of Physics and Astronomy, University of Nebraska-Lincoln, Lincoln, NE, 68588, USA
| | - Valerii M Vinokur
- University of Picardie, Laboratory of Condensed Matter Physics, Amiens, 80039, France
- Terra Quantum AG, Kornhausstrasse 25, St. Gallen, CH-9000, Switzerland
- Physics Department, City College of the City University of New York, 160 Convent Avenue, New York, NY, 10031, USA
| | - Igor Luk'yanchuk
- University of Picardie, Laboratory of Condensed Matter Physics, Amiens, 80039, France
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8
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Ferroelectric Memory Based on Topological Domain Structures: A Phase Field Simulation. CRYSTALS 2022. [DOI: 10.3390/cryst12060786] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The low storage density of ferroelectric thin film memory currently limits the further application of ferroelectric memory. Topologies based on controllable ferroelectric domain structures offer opportunities to develop microelectronic devices such as high-density memories. This study uses ferroelectric topology domains in a ferroelectric field-effect transistor (FeFET) structure for memory. The electrical behavior of FeFET and its flip properties under strain and electric fields are investigated using a phase-field model combined with the device equations of field-effect transistors. When the dimensionless electric field changes from −0.10 to 0.10, the memory window drops from 2.49 V to 0.6 V and the on-state current drops from 2.511 mA to 1.951 mA; the off-state current grows from 1.532 mA to 1.877 mA. External tensile stress increases the memory window and off-state current, while compressive stress decreases it. This study shows that a ferroelectric topology can be used as memory and could significantly increase the storage density of ferroelectric memory.
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9
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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: 2] [Impact Index Per Article: 1.0] [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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10
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Ai Y, Lv HP, Wang ZX, Liao WQ, Xiong RG. H/F substitution for advanced molecular ferroelectrics. TRENDS IN CHEMISTRY 2021. [DOI: 10.1016/j.trechm.2021.09.010] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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11
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Zhang HY, Chen XG, Tang YY, Liao WQ, Di FF, Mu X, Peng H, Xiong RG. PFM (piezoresponse force microscopy)-aided design for molecular ferroelectrics. Chem Soc Rev 2021; 50:8248-8278. [PMID: 34081064 DOI: 10.1039/c9cs00504h] [Citation(s) in RCA: 43] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
With prosperity, decay, and another spring, molecular ferroelectrics have passed a hundred years since Valasek first discovered ferroelectricity in the molecular compound Rochelle salt. Recently, the proposal of ferroelectrochemistry has injected new vigor into this century-old research field. It should be highlighted that piezoresponse force microscopy (PFM) technique, as a non-destructive imaging and manipulation method for ferroelectric domains at the nanoscale, can significantly speed up the design rate of molecular ferroelectrics as well as enhance the ferroelectric and piezoelectric performances relying on domain engineering. Herein, we provide a brief review of the contribution of the PFM technique toward assisting the design and performance optimization of molecular ferroelectrics. Relying on the relationship between ferroelectric domains and crystallography, together with other physical characteristics such as domain switching and piezoelectricity, we believe that the PFM technique can be effectively applied to assist the design of high-performance molecular ferroelectrics equipped with multifunctionality, and thereby facilitate their practical utilization in optics, electronics, magnetics, thermotics, and mechanics among others.
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Affiliation(s)
- Han-Yue Zhang
- Ordered Matter Science Research Center, Nanchang University, Nanchang 330031, P. R. China.
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12
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Chen S, Yuan S, Hou Z, Tang Y, Zhang J, Wang T, Li K, Zhao W, Liu X, Chen L, Martin LW, Chen Z. Recent Progress on Topological Structures in Ferroic Thin Films and Heterostructures. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2021; 33:e2000857. [PMID: 32815214 DOI: 10.1002/adma.202000857] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/06/2020] [Revised: 04/17/2020] [Indexed: 06/11/2023]
Abstract
Topological spin/polarization structures in ferroic materials continue to draw great attention as a result of their fascinating physical behaviors and promising applications in the field of high-density nonvolatile memories as well as future energy-efficient nanoelectronic and spintronic devices. Such developments have been made, in part, based on recent advances in theoretical calculations, the synthesis of high-quality thin films, and the characterization of their emergent phenomena and exotic phases. Herein, progress over the last decade in the study of topological structures in ferroic thin films and heterostructures is explored, including the observation of topological structures and control of their structures and emergent physical phenomena through epitaxial strain, layer thickness, electric, magnetic fields, etc. First, the evolution of topological spin structures (e.g., magnetic skyrmions) and associated functionalities (e.g., topological Hall effect) in magnetic thin films and heterostructures is discussed. Then, the exotic polar topologies (e.g., domain walls, closure domains, polar vortices, bubble domains, and polar skyrmions) and their emergent physical properties in ferroelectric oxide films and heterostructures are explored. Finally, a brief overview and prospectus of how the field may evolve in the coming years is provided.
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Affiliation(s)
- Shanquan Chen
- School of Materials Science and Engineering, Harbin Institute of Technology, Shenzhen, 518055, China
| | - Shuai Yuan
- School of Materials Science and Engineering, Harbin Institute of Technology, Shenzhen, 518055, China
| | - Zhipeng Hou
- Guangdong Provincial Key Laboratory of Optical Information Materials and Technology & Institute for Advanced Materials, South China Academy of Advanced Optoelectronics, South China Normal University, Guangzhou, 510006, P. R. China
- National Center for International Research on Green Optoelectronics, South China Normal University, Guangzhou, 510006, P. R. China
| | - Yunlong Tang
- Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Wenhua Road 72, Shenyang, 110016, China
| | - Jinping Zhang
- School of Materials Science and Engineering, Harbin Institute of Technology, Shenzhen, 518055, China
| | - Tao Wang
- School of Materials Science and Engineering, Harbin Institute of Technology, Shenzhen, 518055, China
| | - Kang Li
- Flexible Printed Electronics Technology Center, Harbin Institute of Technology, Shenzhen, 518055, China
| | - Weiwei Zhao
- School of Materials Science and Engineering, Harbin Institute of Technology, Shenzhen, 518055, China
- Flexible Printed Electronics Technology Center, Harbin Institute of Technology, Shenzhen, 518055, China
| | - Xingjun Liu
- School of Materials Science and Engineering, Harbin Institute of Technology, Shenzhen, 518055, China
| | - Lang Chen
- Department of Physics, Southern University of Science and Technology, Shenzhen, 518055, China
| | - Lane W Martin
- Department of Materials Science and Engineering, University of California, Berkeley, CA, 94720, USA
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Zuhuang Chen
- School of Materials Science and Engineering, Harbin Institute of Technology, Shenzhen, 518055, China
- Flexible Printed Electronics Technology Center, Harbin Institute of Technology, Shenzhen, 518055, China
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13
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Ai Y, Zeng YL, He WH, Huang XQ, Tang YY. Six-Fold Vertices in a Single-Component Organic Ferroelectric with Most Equivalent Polarization Directions. J Am Chem Soc 2020; 142:13989-13995. [DOI: 10.1021/jacs.0c06936] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
- Yong Ai
- Ordered Matter Science Research Center, Nanchang University, Nanchang 330031, People’s Republic of China
| | - Yu-Ling Zeng
- Ordered Matter Science Research Center, Nanchang University, Nanchang 330031, People’s Republic of China
| | - Wen-Hui He
- Ordered Matter Science Research Center, Nanchang University, Nanchang 330031, People’s Republic of China
| | - Xue-Qin Huang
- Ordered Matter Science Research Center, Nanchang University, Nanchang 330031, People’s Republic of China
| | - Yuan-Yuan Tang
- Ordered Matter Science Research Center, Nanchang University, Nanchang 330031, People’s Republic of China
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14
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McConville JPV, Lu H, Wang B, Tan Y, Cochard C, Conroy M, Moore K, Harvey A, Bangert U, Chen L, Gruverman A, Gregg JM. Ferroelectric Domain Wall Memristor. ADVANCED FUNCTIONAL MATERIALS 2020; 30:2000109. [PMID: 32684905 PMCID: PMC7357591 DOI: 10.1002/adfm.202000109] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/06/2020] [Revised: 03/27/2020] [Accepted: 04/08/2020] [Indexed: 05/31/2023]
Abstract
A domain wall-enabled memristor is created, in thin film lithium niobate capacitors, which shows up to twelve orders of magnitude variation in resistance. Such dramatic changes are caused by the injection of strongly inclined conducting ferroelectric domain walls, which provide conduits for current flow between electrodes. Varying the magnitude of the applied electric-field pulse, used to induce switching, alters the extent to which polarization reversal occurs; this systematically changes the density of the injected conducting domain walls in the ferroelectric layer and hence the resistivity of the capacitor structure as a whole. Hundreds of distinct conductance states can be produced, with current maxima achieved around the coercive voltage, where domain wall density is greatest, and minima associated with the almost fully switched ferroelectric (few domain walls). Significantly, this "domain wall memristor" demonstrates a plasticity effect: when a succession of voltage pulses of constant magnitude is applied, the resistance changes. Resistance plasticity opens the way for the domain wall memristor to be considered for artificial synapse applications in neuromorphic circuits.
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Affiliation(s)
- James P. V. McConville
- Centre for Nanostructured MediaSchool of Mathematics and PhysicsQueen's University BelfastBelfastBT7 1NNUK
| | - Haidong Lu
- Physics and AstronomyUniversity of Nebraska‐LincolnLincolnNebraska68588‐0299USA
| | - Bo Wang
- Department of Materials Science and EngineeringPennsylvania State University221 Steidle BuildingUniversity ParkPA16802USA
| | - Yueze Tan
- Department of Materials Science and EngineeringPennsylvania State University221 Steidle BuildingUniversity ParkPA16802USA
| | - Charlotte Cochard
- Centre for Nanostructured MediaSchool of Mathematics and PhysicsQueen's University BelfastBelfastBT7 1NNUK
| | - Michele Conroy
- Department of PhysicsSchool of Sciences and Bernal InstituteUniversity of LimerickLimerickV94 T9PXIreland
| | - Kalani Moore
- Department of PhysicsSchool of Sciences and Bernal InstituteUniversity of LimerickLimerickV94 T9PXIreland
| | - Alan Harvey
- Department of PhysicsSchool of Sciences and Bernal InstituteUniversity of LimerickLimerickV94 T9PXIreland
| | - Ursel Bangert
- Department of PhysicsSchool of Sciences and Bernal InstituteUniversity of LimerickLimerickV94 T9PXIreland
| | - Long‐Qing Chen
- Department of Materials Science and EngineeringPennsylvania State University221 Steidle BuildingUniversity ParkPA16802USA
| | - Alexei Gruverman
- Physics and AstronomyUniversity of Nebraska‐LincolnLincolnNebraska68588‐0299USA
| | - J. Marty Gregg
- Centre for Nanostructured MediaSchool of Mathematics and PhysicsQueen's University BelfastBelfastBT7 1NNUK
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15
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Liu R, Ulbrandt JG, Hsing HC, Gura A, Bein B, Sun A, Pan C, Bertino G, Lai A, Cheng K, Doyle E, Evans-Lutterodt K, Headrick RL, Dawber M. Role of ferroelectric polarization during growth of highly strained ferroelectric materials. Nat Commun 2020; 11:2630. [PMID: 32457379 PMCID: PMC7251112 DOI: 10.1038/s41467-020-16356-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2019] [Accepted: 04/20/2020] [Indexed: 11/24/2022] Open
Abstract
In ferroelectric thin films and superlattices, the polarization is intricately linked to crystal structure. Here we show that it can also play an important role in the growth process, influencing growth rates, relaxation mechanisms, electrical properties and domain structures. This is studied by focusing on the properties of BaTiO3 thin films grown on very thin layers of PbTiO3 using x-ray diffraction, piezoforce microscopy, electrical characterization and rapid in-situ x-ray diffraction reciprocal space maps during the growth using synchrotron radiation. Using a simple model we show that the changes in growth are driven by the energy cost for the top material to sustain the polarization imposed upon it by the underlying layer, and these effects may be expected to occur in other multilayer systems where polarization is present during growth. This motivates the concept of polarization engineering as a complementary approach to strain engineering. Ferroelectric (FE) materials are used in a wide range of applications, which often requires sizable FE polarization. Here, the authors report a growth procedure to enhance the FE polarization by exploiting the polarization of a FE substrate during growth to obtain higher strains and polarizations in the final material.
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Affiliation(s)
- Rui Liu
- Department of Physics and Astronomy, Stony Brook University, Stony Brook, NY, 11794-3800, USA
| | - Jeffrey G Ulbrandt
- Department of Physics and Materials Science Program, University of Vermont, Burlington, VT, 05405, USA
| | - Hsiang-Chun Hsing
- Department of Physics and Astronomy, Stony Brook University, Stony Brook, NY, 11794-3800, USA
| | - Anna Gura
- Department of Physics and Astronomy, Stony Brook University, Stony Brook, NY, 11794-3800, USA
| | - Benjamin Bein
- Department of Physics and Astronomy, Stony Brook University, Stony Brook, NY, 11794-3800, USA
| | - Alec Sun
- Department of Physics and Astronomy, Stony Brook University, Stony Brook, NY, 11794-3800, USA
| | - Charles Pan
- Department of Physics and Astronomy, Stony Brook University, Stony Brook, NY, 11794-3800, USA
| | - Giulia Bertino
- Department of Physics and Astronomy, Stony Brook University, Stony Brook, NY, 11794-3800, USA
| | - Amanda Lai
- Department of Physics and Astronomy, Stony Brook University, Stony Brook, NY, 11794-3800, USA
| | - Kaize Cheng
- Department of Physics and Astronomy, Stony Brook University, Stony Brook, NY, 11794-3800, USA
| | - Eli Doyle
- Department of Physics and Astronomy, Stony Brook University, Stony Brook, NY, 11794-3800, USA
| | | | - Randall L Headrick
- Department of Physics and Materials Science Program, University of Vermont, Burlington, VT, 05405, USA
| | - Matthew Dawber
- Department of Physics and Astronomy, Stony Brook University, Stony Brook, NY, 11794-3800, USA.
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16
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Zhang HY, Song XJ, Chen XG, Zhang ZX, You YM, Tang YY, Xiong RG. Observation of Vortex Domains in a Two-Dimensional Lead Iodide Perovskite Ferroelectric. J Am Chem Soc 2020; 142:4925-4931. [PMID: 32053353 DOI: 10.1021/jacs.0c00371] [Citation(s) in RCA: 98] [Impact Index Per Article: 24.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Topological defects, such as vortices and skyrmions, provide a wealth of splendid possibilities for new nanoscale devices because of their marvelous electronic, magnetic, and mechanical behaviors. Recently, great advances have been made in the study of the ferroelectric vortex in conventional perovskite oxides, such as BaTiO3 and BiFeO3. Despite extensive interest, however, no intriguing ferroelectric vortex structures have yet been found in organic-inorganic hybrid perovskites (OIHPs), which are desirable for their mechanical flexibility, ease of fabrication, and low acoustical impedance. We observed the robust vortex-antivortex topological configurations in a two-dimensional (2D) layered OIHP ferroelectric (4,4-DFPD)2PbI4 (4,4-DFPD is 4,4-difluoropiperidinium). This provides future directions for the study of perovskites and makes it a promising alternative for nanoscale ferroelectric devices in medical, micromechanical, and biomechanical applications.
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Affiliation(s)
- Han-Yue Zhang
- Jiangsu Key Laboratory for Science and Applications of Molecular Ferroelectrics, Southeast University, Nanjing 211189, People's Republic of China
| | - Xian-Jiang Song
- Jiangsu Key Laboratory for Science and Applications of Molecular Ferroelectrics, Southeast University, Nanjing 211189, People's Republic of China
| | - Xiao-Gang Chen
- Jiangsu Key Laboratory for Science and Applications of Molecular Ferroelectrics, Southeast University, Nanjing 211189, People's Republic of China
| | - Zhi-Xu Zhang
- Jiangsu Key Laboratory for Science and Applications of Molecular Ferroelectrics, Southeast University, Nanjing 211189, People's Republic of China
| | - Yu-Meng You
- Jiangsu Key Laboratory for Science and Applications of Molecular Ferroelectrics, Southeast University, Nanjing 211189, People's Republic of China
| | - Yuan-Yuan Tang
- Ordered Matter Science Research Center, Nanchang University, Nanchang 330031, People's Republic of China
| | - Ren-Gen Xiong
- Jiangsu Key Laboratory for Science and Applications of Molecular Ferroelectrics, Southeast University, Nanjing 211189, People's Republic of China.,Ordered Matter Science Research Center, Nanchang University, Nanchang 330031, People's Republic of China
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17
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Tian G, Yang W, Chen D, Fan Z, Hou Z, Alexe M, Gao X. Topological domain states and magnetoelectric properties in multiferroic nanostructures. Natl Sci Rev 2019; 6:684-702. [PMID: 34691923 PMCID: PMC8291546 DOI: 10.1093/nsr/nwz100] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2019] [Revised: 07/07/2019] [Accepted: 07/12/2019] [Indexed: 11/21/2022] Open
Abstract
Multiferroic nanostructures have been attracting tremendous attention over the past decade, due to their rich cross-coupling effects and prospective electronic applications. In particular, the emergence of some exotic phenomena in size-confined multiferroic systems, including topological domain states such as vortices, center domains, and skyrmion bubble domains, has opened a new avenue to a number of intriguing physical properties and functionalities, and thus underpins a wide range of applications in future nanoelectronic devices. It is also highly appreciated that nano-domain engineering provides a pathway to control the magnetoelectric properties, which is promising for future energy-efficient spintronic devices. In recent years, this field, still in its infancy, has witnessed a rapid development and a number of challenges too. In this article, we shall review the recent advances in the emergent domain-related exotic phenomena in multiferroic nanostructures. Specific attention is paid to the topological domain structures and related novel physical behaviors as well as the electric-field-driven magnetic switching via domain engineering. This review will end with a discussion of future challenges and potential directions.
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Affiliation(s)
- Guo Tian
- Guangdong Provincial Key Laboratory of Quantum Engineering and Quantum Materials, and Institute for Advanced Materials, South China Academy of Advanced Optoelectronics, South China Normal University, Guangzhou 510006, China
| | - Wenda Yang
- Guangdong Provincial Key Laboratory of Quantum Engineering and Quantum Materials, and Institute for Advanced Materials, South China Academy of Advanced Optoelectronics, South China Normal University, Guangzhou 510006, China
| | - Deyang Chen
- Guangdong Provincial Key Laboratory of Quantum Engineering and Quantum Materials, and Institute for Advanced Materials, South China Academy of Advanced Optoelectronics, South China Normal University, Guangzhou 510006, China
| | - Zhen Fan
- Guangdong Provincial Key Laboratory of Quantum Engineering and Quantum Materials, and Institute for Advanced Materials, South China Academy of Advanced Optoelectronics, South China Normal University, Guangzhou 510006, China
| | - Zhipeng Hou
- Guangdong Provincial Key Laboratory of Quantum Engineering and Quantum Materials, and Institute for Advanced Materials, South China Academy of Advanced Optoelectronics, South China Normal University, Guangzhou 510006, China
| | - Marin Alexe
- Department of Physics, University of Warwick, Coventry CV4 7AL, UK
| | - Xingsen Gao
- Guangdong Provincial Key Laboratory of Quantum Engineering and Quantum Materials, and Institute for Advanced Materials, South China Academy of Advanced Optoelectronics, South China Normal University, Guangzhou 510006, China
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18
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Gruverman A, Alexe M, Meier D. Piezoresponse force microscopy and nanoferroic phenomena. Nat Commun 2019; 10:1661. [PMID: 30971688 PMCID: PMC6458164 DOI: 10.1038/s41467-019-09650-8] [Citation(s) in RCA: 119] [Impact Index Per Article: 23.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2017] [Accepted: 03/05/2019] [Indexed: 11/23/2022] Open
Abstract
Since its inception more than 25 years ago, Piezoresponse Force Microscopy (PFM) has become one of the mainstream techniques in the field of nanoferroic materials. This review describes the evolution of PFM from an imaging technique to a set of advanced methods, which have played a critical role in launching new areas of ferroic research, such as multiferroic devices and domain wall nanoelectronics. The paper reviews the impact of advanced PFM modes concerning the discovery and scientific understanding of novel nanoferroic phenomena and discusses challenges associated with the correct interpretation of PFM data. In conclusion, it offers an outlook for future trends and developments in PFM.
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Affiliation(s)
- Alexei Gruverman
- Department of Physics and Astronomy, University of Nebraska, Lincoln, NE, 68588, USA.
| | - Marin Alexe
- Department of Physics, University of Warwick, Coventry, CV4 7AL, UK
| | - Dennis Meier
- Department of Materials Science and Engineering, Norwegian University of Science and Technology (NTNU), N-7034, Trondheim, Norway
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19
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Kalinin SV, Kim Y, Fong DD, Morozovska AN. Surface-screening mechanisms in ferroelectric thin films and their effect on polarization dynamics and domain structures. REPORTS ON PROGRESS IN PHYSICS. PHYSICAL SOCIETY (GREAT BRITAIN) 2018; 81:036502. [PMID: 29368693 DOI: 10.1088/1361-6633/aa915a] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
For over 70 years, ferroelectric materials have been one of the central research topics for condensed matter physics and material science, an interest driven both by fundamental science and applications. However, ferroelectric surfaces, the key component of ferroelectric films and nanostructures, still present a significant theoretical and even conceptual challenge. Indeed, stability of ferroelectric phase per se necessitates screening of polarization charge. At surfaces, this can lead to coupling between ferroelectric and semiconducting properties of material, or with surface (electro) chemistry, going well beyond classical models applicable for ferroelectric interfaces. In this review, we summarize recent studies of surface-screening phenomena in ferroelectrics. We provide a brief overview of the historical understanding of the physics of ferroelectric surfaces, and existing theoretical models that both introduce screening mechanisms and explore the relationship between screening and relevant aspects of ferroelectric functionalities starting from phase stability itself. Given that the majority of ferroelectrics exist in multiple-domain states, we focus on local studies of screening phenomena using scanning probe microscopy techniques. We discuss recent studies of static and dynamic phenomena on ferroelectric surfaces, as well as phenomena observed under lateral transport, light, chemical, and pressure stimuli. We also note that the need for ionic screening renders polarization switching a coupled physical-electrochemical process and discuss the non-trivial phenomena such as chaotic behavior during domain switching that stem from this.
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Affiliation(s)
- Sergei V Kalinin
- The Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN 37831, United States of America
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20
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Kim KE, Jeong S, Chu K, Lee JH, Kim GY, Xue F, Koo TY, Chen LQ, Choi SY, Ramesh R, Yang CH. Configurable topological textures in strain graded ferroelectric nanoplates. Nat Commun 2018; 9:403. [PMID: 29374260 PMCID: PMC5785989 DOI: 10.1038/s41467-017-02813-5] [Citation(s) in RCA: 72] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2017] [Accepted: 12/28/2017] [Indexed: 11/20/2022] Open
Abstract
Topological defects in matter behave collectively to form highly non-trivial structures called topological textures that are characterised by conserved quantities such as the winding number. Here we show that an epitaxial ferroelectric square nanoplate of bismuth ferrite subjected to a large strain gradient (as much as 105 m−1) associated with misfit strain relaxation enables five discrete levels for the ferroelectric topological invariant of the entire system because of its peculiar radial quadrant domain texture and its inherent domain wall chirality. The total winding number of the topological texture can be configured from − 1 to 3 by selective non-local electric switching of the quadrant domains. By using angle-resolved piezoresponse force microscopy in conjunction with local winding number analysis, we directly identify the existence of vortices and anti-vortices, observe pair creation and annihilation and manipulate the net number of vortices. Our findings offer a useful concept for multi-level topological defect memory. Exploring topological textures in ferroelectrics facilitates the understanding and application of topological features in matter. Here the authors demonstrate the strain field induced evolution of topological vortices in nanoplatelets of rhombohedral phase BiFeO3 using the angle-resolved piezoresponse force microscopy.
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Affiliation(s)
- Kwang-Eun Kim
- Department of Physics, Korea Advanced Institute of Science and Technology (KAIST), Yuseong-gu, Daejeon, 34141, Republic of Korea
| | - Seuri Jeong
- Department of Physics, Korea Advanced Institute of Science and Technology (KAIST), Yuseong-gu, Daejeon, 34141, Republic of Korea
| | - Kanghyun Chu
- Department of Physics, Korea Advanced Institute of Science and Technology (KAIST), Yuseong-gu, Daejeon, 34141, Republic of Korea
| | - Jin Hong Lee
- Department of Physics, Korea Advanced Institute of Science and Technology (KAIST), Yuseong-gu, Daejeon, 34141, Republic of Korea
| | - Gi-Yeop Kim
- Department of Materials Modelling and Characterization, Korea Institute of Materials Science, Changwon, Gyeongnam, 51508, Republic of Korea.,Department of Materials Science and Engineering, Pusan National University, Geumjeong-gu, Busan, 46241, Republic of Korea
| | - Fei Xue
- Department of Materials Science and Engineering, The Pennsylvania State University, University Park, PA, 16802, USA
| | - Tae Yeong Koo
- Pohang Accelerator Laboratory, POSTECH, Pohang, Gyeongbuk, 37673, Republic of Korea
| | - Long-Qing Chen
- Department of Materials Science and Engineering, The Pennsylvania State University, University Park, PA, 16802, USA
| | - Si-Young Choi
- Department of Materials Modelling and Characterization, Korea Institute of Materials Science, Changwon, Gyeongnam, 51508, Republic of Korea.,Department of Materials Science and Engineering, POSTECH, Pohang, Gyeongbuk, 37673, Republic of Korea
| | - Ramamoorthy Ramesh
- Department of Materials Science and Engineering, University of California, Berkeley, CA, 94720, USA.,Department of Physics, University of California, Berkeley, CA, 94720, USA.,Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Chan-Ho Yang
- Department of Physics, Korea Advanced Institute of Science and Technology (KAIST), Yuseong-gu, Daejeon, 34141, Republic of Korea. .,KAIST Institute for the NanoCentury, KAIST, Yuseong-gu, Daejeon, 34141, Republic of Korea.
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21
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Liu Y, Wang YJ, Zhu YL, Lei CH, Tang YL, Li S, Zhang SR, Li J, Ma XL. Large Scale Two-Dimensional Flux-Closure Domain Arrays in Oxide Multilayers and Their Controlled Growth. NANO LETTERS 2017; 17:7258-7266. [PMID: 29125773 DOI: 10.1021/acs.nanolett.7b02615] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Ferroelectric flux-closures are very promising in high-density storage and other nanoscale electronic devices. To make the data bits addressable, the nanoscale flux-closures are required to be periodic via a controlled growth. Although flux-closure quadrant arrays with 180° domain walls perpendicular to the interfaces (V-closure) have been observed in strained ferroelectric PbTiO3 films, the flux-closure quadrants therein are rather asymmetric. In this work, we report not only a periodic array of the symmetric flux-closure quadrants with 180° domain walls parallel to the interfaces (H-closure) but also a large scale alternative stacking of the V- and H-closure arrays in PbTiO3/SrTiO3 multilayers. On the basis of a combination of aberration-corrected scanning transmission electron microscopic imaging and phase field modeling, we establish the phase diagram in the layer-by-layer two-dimensional arrays versus the thickness ratio of adjacent PbTiO3 films, in which energy competitions play dominant roles. The manipulation of these flux-closures may stimulate the design and development of novel nanoscale ferroelectric devices with exotic properties.
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Affiliation(s)
- Ying Liu
- Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences , Wenhua Road 72, 110016 Shenyang, China
| | - Yu-Jia Wang
- Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences , Wenhua Road 72, 110016 Shenyang, China
| | - Yin-Lian Zhu
- Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences , Wenhua Road 72, 110016 Shenyang, China
| | - Chi-Hou Lei
- Department of Aerospace and Mechanical Engineering, Saint Louis University , Saint Louis, Missouri 63103-1110, United States
| | - Yun-Long Tang
- Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences , Wenhua Road 72, 110016 Shenyang, China
| | - Shuang Li
- Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences , Wenhua Road 72, 110016 Shenyang, China
| | - Si-Rui Zhang
- Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences , Wenhua Road 72, 110016 Shenyang, China
| | - Jiangyu Li
- Shenzhen Key Laboratory of Nanobiomechanics, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences , University Town of Shenzhen, Shenzhen, Guangdong 518055, China
- Department of Mechanical Engineering, University of Washington , Seattle, Washington 98195-2600, United States
| | - Xiu-Liang Ma
- Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences , Wenhua Road 72, 110016 Shenyang, China
- School of Materials Science and Engineering, Lanzhou University of Technology , 730050 Lanzhou, China
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22
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Zhang Q, Xie L, Liu G, Prokhorenko S, Nahas Y, Pan X, Bellaiche L, Gruverman A, Valanoor N. Nanoscale Bubble Domains and Topological Transitions in Ultrathin Ferroelectric Films. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2017; 29:1702375. [PMID: 29064154 DOI: 10.1002/adma.201702375] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2017] [Revised: 07/10/2017] [Indexed: 06/07/2023]
Abstract
Observation of a new type of nanoscale ferroelectric domains, termed as "bubble domains"-laterally confined spheroids of sub-10 nm size with local dipoles self-aligned in a direction opposite to the macroscopic polarization of a surrounding ferroelectric matrix-is reported. The bubble domains appear in ultrathin epitaxial PbZr0.2 Ti0.8 O3 /SrTiO3 /PbZr0.2 Ti0.8 O3 ferroelectric sandwich structures due to the interplay between charge and lattice degrees of freedom. The existence of the bubble domains is revealed by high-resolution piezoresponse force microscopy (PFM), and is corroborated by aberration-corrected atomic-resolution scanning transmission electron microscopy mapping of the polarization displacements. An incommensurate phase and symmetry breaking is found within these domains resulting in local polarization rotation and hence impart a mixed Néel-Bloch-like character to the bubble domain walls. PFM hysteresis loops for the bubble domains reveal that they undergo an irreversible phase transition to cylindrical domains under the electric field, accompanied by a transient rise in the electromechanical response. The observations are in agreement with ab-initio-based calculations, which reveal a very narrow window of electrical and elastic parameters that allow the existence of bubble domains. The findings highlight the richness of polar topologies possible in ultrathin ferroelectric structures and bring forward the prospect of emergent functionalities due to topological transitions.
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Affiliation(s)
- Qi Zhang
- School of Materials Science and Engineering, The University of New South Wales, Sydney, New South Wales, 2052, Australia
| | - Lin Xie
- National Laboratory of Solid State Microstructures and Department of Materials Science and Engineering, Nanjing University, Nanjing, 210093, P. R. China
- Department of Chemical Engineering and Materials Science, University of California, Irvine, CA, 92697, USA
| | - Guangqing Liu
- School of Materials Science and Engineering, The University of New South Wales, Sydney, New South Wales, 2052, Australia
| | - Sergei Prokhorenko
- Theoretical Materials Physics Q-MAT CESAM, University of Liège, Sart Tilman, B-4000, Belgium
- Physics Department and Institute for Nanoscience and Engineering, University of Arkansas, Fayetteville, AR, 72701, USA
| | - Yousra Nahas
- Physics Department and Institute for Nanoscience and Engineering, University of Arkansas, Fayetteville, AR, 72701, USA
| | - Xiaoqing Pan
- Department of Chemical Engineering and Materials Science, University of California, Irvine, CA, 92697, USA
- Department of Physics and Astronomy, University of California, Irvine, CA, 92697, USA
| | - Laurent Bellaiche
- Physics Department and Institute for Nanoscience and Engineering, University of Arkansas, Fayetteville, AR, 72701, USA
| | - Alexei Gruverman
- Department of Physics and Astronomy, University of Nebraska, Lincoln, NE, 68588, USA
| | - Nagarajan Valanoor
- School of Materials Science and Engineering, The University of New South Wales, Sydney, New South Wales, 2052, Australia
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23
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Field enhancement of electronic conductance at ferroelectric domain walls. Nat Commun 2017; 8:1318. [PMID: 29105653 PMCID: PMC5673066 DOI: 10.1038/s41467-017-01334-5] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2017] [Accepted: 09/08/2017] [Indexed: 11/22/2022] Open
Abstract
Ferroelectric domain walls have continued to attract widespread attention due to both the novelty of the phenomena observed and the ability to reliably pattern them in nanoscale dimensions. However, the conductivity mechanisms remain in debate, particularly around nominally uncharged walls. Here, we posit a conduction mechanism relying on field-modification effect from polarization re-orientation and the structure of the reverse-domain nucleus. Through conductive atomic force microscopy measurements on an ultra-thin (001) BiFeO3 thin film, in combination with phase-field simulations, we show that the field-induced twisted domain nucleus formed at domain walls results in local-field enhancement around the region of the atomic force microscope tip. In conjunction with slight barrier lowering, these two effects are sufficient to explain the observed emission current distribution. These results suggest that different electronic properties at domain walls are not necessary to observe localized enhancement in domain wall currents. Understanding the conductivity at the nominally uncharged domain walls in ferroelectrics is still far from complete. Here the authors report an enhanced conduction at domain walls in an ultra-thin (001) BiFeO3 film resulting from the formation of a field-induced meta-stable twisted domain nucleus.
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24
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Van Lich L, Shimada T, Wang J, Kitamura T. Self-ordering of nontrivial topological polarization structures in nanoporous ferroelectrics. NANOSCALE 2017; 9:15525-15533. [PMID: 28980678 DOI: 10.1039/c7nr04661h] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Topological field structures, such as skyrmions, merons, and vortices, are important features found in ordered systems with spontaneously broken symmetry. A plethora of topological field structures have been discovered in magnetic and ordered soft matter systems due to the presence of inherent chiral interactions, and this has provided a fruitful platform for unearthing additional groundbreaking functionalities. However, despite being one of the most important classes of ordered systems, ferroelectrics scarcely form topological polarization structures due to their lack of intrinsic chiral interactions. In the present study, we demonstrate using multiphysics phase-field modelling based on the Ginzburg-Landau theory that a rich assortment of nontrivial topological polarization structures, including hedgehogs, antivortices, multidirectional vortices, and vortex arrays, can be spontaneously formed in three-dimensional nanoporous ferroelectric structures. We realize that confining ferroelectrics to trivial geometries that are incompatible with the orientation symmetry may impose extrinsic frustration to the polarization field through the enhancement of depolarization fields at free porous surfaces. This frustration gives rise to symmetry breaking, resulting in the formation of nontrivial topological polarization structures as the ground state. We further topologically characterize the local accommodation of polarization structures by viewing them in a new perspective, in which polarization ordering can be mapped on the order parameter space, according to the topological theory of defects and homotopy theory. The results indicate that the nanoporous structures contain composite topological objects composed of two or more elementary topological polarization structures. The present study therefore offers a playground for exploring novel physical phenomena in ferroelectric systems as well as a novel nanoelectronics characterization platform for future topology-based nanotechnologies.
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Affiliation(s)
- Le Van Lich
- Department of Mechanical Engineering and Science, Kyoto University, Nishikyo-ku, Kyoto 615-8540, Japan.
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25
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Zheng Y, Chen WJ. Characteristics and controllability of vortices in ferromagnetics, ferroelectrics, and multiferroics. REPORTS ON PROGRESS IN PHYSICS. PHYSICAL SOCIETY (GREAT BRITAIN) 2017; 80:086501. [PMID: 28155849 DOI: 10.1088/1361-6633/aa5e03] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Topological defects in condensed matter are attracting e significant attention due to their important role in phase transition and their fascinating characteristics. Among the various types of matter, ferroics which possess a switchable physical characteristic and form domain structure are ideal systems to form topological defects. In particular, a special class of topological defects-vortices-have been found to commonly exist in ferroics. They often manifest themselves as singular regions where domains merge in large systems, or stabilize as novel order states instead of forming domain structures in small enough systems. Understanding the characteristics and controllability of vortices in ferroics can provide us with deeper insight into the phase transition of condensed matter and also exciting opportunities in designing novel functional devices such as nano-memories, sensors, and transducers based on topological defects. In this review, we summarize the recent experimental and theoretical progress in ferroic vortices, with emphasis on those spin/dipole vortices formed in nanoscale ferromagnetics and ferroelectrics, and those structural domain vortices formed in multiferroic hexagonal manganites. We begin with an overview of this field. The fundamental concepts of ferroic vortices, followed by the theoretical simulation and experimental methods to explore ferroic vortices, are then introduced. The various characteristics of vortices (e.g. formation mechanisms, static/dynamic features, and electronic properties) and their controllability (e.g. by size, geometry, external thermal, electrical, magnetic, or mechanical fields) in ferromagnetics, ferroelectrics, and multiferroics are discussed in detail in individual sections. Finally, we conclude this review with an outlook on this rapidly developing field.
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Affiliation(s)
- Yue Zheng
- State Key Laboratory of Optoelectronic Materials and Technologies, School of Physics, Sun Yat-sen University, Guangzhou 510275, Guangdong, People's Republic of China. Micro&Nano Physics and Mechanics Research Laboratory, School of Physics, Sun Yat-sen University, Guangzhou 510275, Guangdong, People's Republic of China
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26
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Li Z, Wang Y, Tian G, Li P, Zhao L, Zhang F, Yao J, Fan H, Song X, Chen D, Fan Z, Qin M, Zeng M, Zhang Z, Lu X, Hu S, Lei C, Zhu Q, Li J, Gao X, Liu JM. High-density array of ferroelectric nanodots with robust and reversibly switchable topological domain states. SCIENCE ADVANCES 2017; 3:e1700919. [PMID: 28835925 PMCID: PMC5562417 DOI: 10.1126/sciadv.1700919] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/24/2017] [Accepted: 07/16/2017] [Indexed: 05/04/2023]
Abstract
The exotic topological domains in ferroelectrics and multiferroics have attracted extensive interest in recent years due to their novel functionalities and potential applications in nanoelectronic devices. One of the key challenges for these applications is a realization of robust yet reversibly switchable nanoscale topological domain states with high density, wherein spontaneous topological structures can be individually addressed and controlled. This has been accomplished in our work using high-density arrays of epitaxial BiFeO3 (BFO) ferroelectric nanodots with a lateral size as small as ~60 nm. We demonstrate various types of spontaneous topological domain structures, including center-convergent domains, center-divergent domains, and double-center domains, which are stable over sufficiently long time but can be manipulated and reversibly switched by electric field. The formation mechanisms of these topological domain states, assisted by the accumulation of compensating charges on the surface, have also been revealed. These results demonstrated that these reversibly switchable topological domain arrays are promising for applications in high-density nanoferroelectric devices such as nonvolatile memories.
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Affiliation(s)
- Zhongwen Li
- Institute for Advanced Materials and Guangdong Provincial Key Laboratory of Quantum Engineering and Quantum Materials, South China Normal University, Guangzhou 510006, China
| | - Yujia Wang
- Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, 72 Wenhua Road, Shenyang 110016, China
| | - Guo Tian
- Institute for Advanced Materials and Guangdong Provincial Key Laboratory of Quantum Engineering and Quantum Materials, South China Normal University, Guangzhou 510006, China
| | - Peilian Li
- Institute for Advanced Materials and Guangdong Provincial Key Laboratory of Quantum Engineering and Quantum Materials, South China Normal University, Guangzhou 510006, China
| | - Lina Zhao
- Institute for Advanced Materials and Guangdong Provincial Key Laboratory of Quantum Engineering and Quantum Materials, South China Normal University, Guangzhou 510006, China
| | - Fengyuan Zhang
- Institute for Advanced Materials and Guangdong Provincial Key Laboratory of Quantum Engineering and Quantum Materials, South China Normal University, Guangzhou 510006, China
| | - Junxiang Yao
- Institute for Advanced Materials and Guangdong Provincial Key Laboratory of Quantum Engineering and Quantum Materials, South China Normal University, Guangzhou 510006, China
| | - Hua Fan
- Institute for Advanced Materials and Guangdong Provincial Key Laboratory of Quantum Engineering and Quantum Materials, South China Normal University, Guangzhou 510006, China
| | - Xiao Song
- Institute for Advanced Materials and Guangdong Provincial Key Laboratory of Quantum Engineering and Quantum Materials, South China Normal University, Guangzhou 510006, China
| | - Deyang Chen
- Institute for Advanced Materials and Guangdong Provincial Key Laboratory of Quantum Engineering and Quantum Materials, South China Normal University, Guangzhou 510006, China
| | - Zhen Fan
- Institute for Advanced Materials and Guangdong Provincial Key Laboratory of Quantum Engineering and Quantum Materials, South China Normal University, Guangzhou 510006, China
| | - Minghui Qin
- Institute for Advanced Materials and Guangdong Provincial Key Laboratory of Quantum Engineering and Quantum Materials, South China Normal University, Guangzhou 510006, China
| | - Min Zeng
- Institute for Advanced Materials and Guangdong Provincial Key Laboratory of Quantum Engineering and Quantum Materials, South China Normal University, Guangzhou 510006, China
| | - Zhang Zhang
- Institute for Advanced Materials and Guangdong Provincial Key Laboratory of Quantum Engineering and Quantum Materials, South China Normal University, Guangzhou 510006, China
| | - Xubing Lu
- Institute for Advanced Materials and Guangdong Provincial Key Laboratory of Quantum Engineering and Quantum Materials, South China Normal University, Guangzhou 510006, China
| | - Shejun Hu
- Institute for Advanced Materials and Guangdong Provincial Key Laboratory of Quantum Engineering and Quantum Materials, South China Normal University, Guangzhou 510006, China
| | - Chihou Lei
- Department of Aerospace and Mechanical Engineering, Saint Louis University, St. Louis, MO 63103–1110, USA
| | - Qingfeng Zhu
- Shenzhen Key Laboratory of Nanobiomechanics, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, Guangdong 518055, China
| | - Jiangyu Li
- Shenzhen Key Laboratory of Nanobiomechanics, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, Guangdong 518055, China
- Department of Mechanical Engineering, University of Washington, Seattle, WA 98195–2600, USA
| | - Xingsen Gao
- Institute for Advanced Materials and Guangdong Provincial Key Laboratory of Quantum Engineering and Quantum Materials, South China Normal University, Guangzhou 510006, China
- Corresponding author. (X.G.); (J.-M.L.)
| | - Jun-Ming Liu
- Institute for Advanced Materials and Guangdong Provincial Key Laboratory of Quantum Engineering and Quantum Materials, South China Normal University, Guangzhou 510006, China
- National Laboratory of Solid State Microstructures and Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 21009, China
- Corresponding author. (X.G.); (J.-M.L.)
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Narayanan A, Cao D, Frazer L, Tayi AS, Blackburn AK, Sue ACH, Ketterson JB, Stoddart JF, Stupp SI. Ferroelectric Polarization and Second Harmonic Generation in Supramolecular Cocrystals with Two Axes of Charge-Transfer. J Am Chem Soc 2017; 139:9186-9191. [DOI: 10.1021/jacs.7b02279] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
| | | | | | | | | | | | | | | | - Samuel I. Stupp
- Department
of Medicine and Simpson-Querrey Institute for BioNanotechnology, Northwestern University, Chicago, Illinois 60611, United States
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Sharma P, Zhang Q, Sando D, Lei CH, Liu Y, Li J, Nagarajan V, Seidel J. Nonvolatile ferroelectric domain wall memory. SCIENCE ADVANCES 2017; 3:e1700512. [PMID: 28691100 PMCID: PMC5482552 DOI: 10.1126/sciadv.1700512] [Citation(s) in RCA: 94] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2017] [Accepted: 05/05/2017] [Indexed: 05/23/2023]
Abstract
Ferroelectric domain walls are atomically sharp topological defects that separate regions of uniform polarization. The discovery of electrical conductivity in specific types of walls gave rise to "domain wall nanoelectronics," a technology in which the wall (rather than the domain) stores information. This paradigm shift critically hinges on precise nanoengineering of reconfigurable domain walls. Using specially designed nanofabricated electrodes and scanning probe techniques, we demonstrate a prototype nonvolatile ferroelectric domain wall memory, scalable to below 100 nm, whose binary state is defined by the existence or absence of conductive walls. The device can be read out nondestructively at moderate voltages (<3 V), exhibits relatively high OFF-ON ratios (~103) with excellent endurance and retention characteristics, and has multilevel data storage capacity. Our work thus constitutes an important step toward integrated nanoscale ferroelectric domain wall memory devices.
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Affiliation(s)
- Pankaj Sharma
- School of Materials Science and Engineering, University of New South Wales Australia, Sydney, New South Wales 2052, Australia
| | - Qi Zhang
- School of Materials Science and Engineering, University of New South Wales Australia, Sydney, New South Wales 2052, Australia
| | - Daniel Sando
- School of Materials Science and Engineering, University of New South Wales Australia, Sydney, New South Wales 2052, Australia
| | - Chi Hou Lei
- Department of Aerospace and Mechanical Engineering, Saint Louis University, St. Louis, MO 63103, USA
| | - Yunya Liu
- School of Materials Science and Engineering and Key Laboratory of Low Dimensional Materials and Application Technology of Ministry of Education, Xiangtan University, Xiangtan, Hunan 411105, China
| | - Jiangyu Li
- Department of Mechanical Engineering, University of Washington, Seattle, WA 98195–2600, USA
- Shenzhen Key Laboratory of Nanobiomechanics, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, Guangdong 518055, China
| | - Valanoor Nagarajan
- School of Materials Science and Engineering, University of New South Wales Australia, Sydney, New South Wales 2052, Australia
| | - Jan Seidel
- School of Materials Science and Engineering, University of New South Wales Australia, Sydney, New South Wales 2052, Australia
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29
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Chapman JBJ, Kimmel AV, Duffy DM. Novel high-temperature ferroelectric domain morphology in PbTiO 3 ultrathin films. Phys Chem Chem Phys 2017; 19:4243-4250. [PMID: 28102380 DOI: 10.1039/c6cp08157f] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Exotic domain morphologies in ferroic materials are an exciting avenue for the development of novel nanoelectronics. In this work we have used large scale molecular dynamics to construct a strain-temperature phase diagram of the domain morphology of PbTiO3 ultrathin films. Sampling a wide interval of strain values over a temperature range up to the Curie temperature Tc, we found that epitaxial strain induces the formation of a variety of closure- and in-plane domain morphologies. The local strain and ferroelectric-antiferrodistortive coupling at the film surface vary for the strain mediated transition sequence and this could offer a route for experimental observation of the morphologies. Remarkably, we identify a new nanobubble domain morphology that is stable in the high-temperature regime for compressively strained PbTiO3. We demonstrate that the formation mechanism of the nanobubble domains morphology is related to the wandering of flux closure domain walls, which we characterise using the hypertoroidal moment. These results provide insight into the local behaviour and dynamics of ferroelectric domains in ultrathin films to open up potential applications for bubble domains in new technologies and pathways to control and exploit novel phenomena in dimensionally constrained materials.
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Affiliation(s)
- Jacob B J Chapman
- Department of Physics and Astronomy, University College London, Gower Street, London, WC1E 6BT, UK. and National Physical Laboratory, Hampton Road, Teddington, TW11 0LW, UK
| | - Anna V Kimmel
- Department of Physics and Astronomy, University College London, Gower Street, London, WC1E 6BT, UK. and National Physical Laboratory, Hampton Road, Teddington, TW11 0LW, UK
| | - Dorothy M Duffy
- Department of Physics and Astronomy, University College London, Gower Street, London, WC1E 6BT, UK.
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30
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Huang HH, Hong Z, Xin HL, Su D, Chen LQ, Huang G, Munroe PR, Valanoor N. Nanoscale Origins of Ferroelastic Domain Wall Mobility in Ferroelectric Multilayers. ACS NANO 2016; 10:10126-10134. [PMID: 27797485 DOI: 10.1021/acsnano.6b05180] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
The nanoscale origins of ferroelastic domain wall motion in ferroelectric multilayer thin films that lead to giant electromechanical responses are investigated. We present direct evidence for complex underpinning factors that result in ferroelastic domain wall mobility using a combination of atomic-level aberration corrected scanning transmission electron microscopy and phase-field simulations in model epitaxial (001) tetragonal (T) PbZrxTi1-xO3 (PZT)/rhombohedral (R) PbZrxTi1-xO3 (PZT) bilayer heterostructures. The local electric dipole distribution is imaged on an atomic scale for a ferroelastic domain wall that nucleates in the R-layer and cuts through the composition breaking the T/R interface. Our studies reveal a highly complex polarization rotation domain structure that is nearly on the knife-edge at the vicinity of this wall. Induced phases, namely tetragonal-like and rhombohedral-like monoclinic were observed close to the interface, and exotic domain arrangements, such as a half-4-fold closure structure, are observed. Phase field simulations show this is due to the minimization of the excessive elastic and electrostatic energies driven by the enormous strain gradient present at the location of the ferroelastic domain walls. Thus, in response to an applied stimulus, such as an electric field, any polarization reorientation must minimize the elastic and electrostatic discontinuities due to this strain gradient, which would induce a dramatic rearrangement of the domain structure. This insight into the origins of ferroelastic domain wall motion will allow researchers to better "craft" such multilayered ferroelectric systems with precisely tailored domain wall functionality and enhanced sensitivity, which can be exploited for the next generation of integrated piezoelectric technologies.
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Affiliation(s)
- Hsin-Hui Huang
- School of Materials Science and Engineering, University of New South Wales , Sydney, New South Wales 2052, Australia
| | - Zijian Hong
- Department of Materials Science and Engineering, Pennsylvania State University , University Park, Pennsylvania 16802-5006, United States
| | - Huolin L Xin
- Center for Functional Nanomaterials, Brookhaven National Laboratory , Upton, New York 11973, United States
| | - Dong Su
- Center for Functional Nanomaterials, Brookhaven National Laboratory , Upton, New York 11973, United States
| | - Long-Qing Chen
- Department of Materials Science and Engineering, Pennsylvania State University , University Park, Pennsylvania 16802-5006, United States
| | - Guanzhong Huang
- Center for Functional Nanomaterials, Brookhaven National Laboratory , Upton, New York 11973, United States
- Department of Materials Science and Engineering, Stony Brook University , Stony Brook, New York 11794-3400, United States
| | - Paul R Munroe
- School of Materials Science and Engineering, University of New South Wales , Sydney, New South Wales 2052, Australia
| | - Nagarajan Valanoor
- School of Materials Science and Engineering, University of New South Wales , Sydney, New South Wales 2052, Australia
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31
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Peters JJP, Apachitei G, Beanland R, Alexe M, Sanchez AM. Polarization curling and flux closures in multiferroic tunnel junctions. Nat Commun 2016; 7:13484. [PMID: 27848970 PMCID: PMC5116095 DOI: 10.1038/ncomms13484] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2016] [Accepted: 10/03/2016] [Indexed: 11/10/2022] Open
Abstract
Formation of domain walls in ferroelectrics is not energetically favourable in low-dimensional systems. Instead, vortex-type structures are formed that are driven by depolarization fields occurring in such systems. Consequently, polarization vortices have only been experimentally found in systems in which these fields are deliberately maximized, that is, in films between insulating layers. As such configurations are devoid of screening charges provided by metal electrodes, commonly used in electronic devices, it is wise to investigate if curling polarization structures are innate to ferroelectricity or induced by the absence of electrodes. Here we show that in unpoled Co/PbTiO3/(La,Sr)MnO3 ferroelectric tunnel junctions, the polarization in active PbTiO3 layers 9 unit cells thick forms Kittel-like domains, while at 6 unit cells there is a complex flux-closure curling behaviour resembling an incommensurate phase. Reducing the thickness to 3 unit cells, there is an almost complete loss of switchable polarization associated with an internal gradient. Ferroelectric vortex-type structures have only been seen in isolated films, leaving electrode effects unexplored. Here, Peters et al. show that the polarisation curling and formation of vortex and flux-closure structures is a generic effect appearing in ultrathin ferroelectric films.
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Affiliation(s)
- Jonathan J P Peters
- Department of Physics, University of Warwick, Gibbet Hill Road, Coventry CV4 7AL, UK
| | - Geanina Apachitei
- Department of Physics, University of Warwick, Gibbet Hill Road, Coventry CV4 7AL, UK
| | - Richard Beanland
- Department of Physics, University of Warwick, Gibbet Hill Road, Coventry CV4 7AL, UK
| | - Marin Alexe
- Department of Physics, University of Warwick, Gibbet Hill Road, Coventry CV4 7AL, UK
| | - Ana M Sanchez
- Department of Physics, University of Warwick, Gibbet Hill Road, Coventry CV4 7AL, UK
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32
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Shimada T, Lich LV, Nagano K, Wang JS, Wang J, Kitamura T. Polar Superhelices in Ferroelectric Chiral Nanosprings. Sci Rep 2016; 6:35199. [PMID: 27713540 PMCID: PMC5054384 DOI: 10.1038/srep35199] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2016] [Accepted: 09/27/2016] [Indexed: 11/09/2022] Open
Abstract
Topological objects of nontrivial spin or dipolar field textures, such as skyrmions, merons, and vortices, interacting with applied external fields in ferroic materials are of great scientific interest as an intriguing playground of unique physical phenomena and novel technological paradigms. The quest for new topological configurations of such swirling field textures has primarily been done for magnets with Dzyaloshinskii-Moriya interactions, while the absence of such intrinsic chiral interactions among electric dipoles left ferroelectrics aside in this quest. Here, we demonstrate that a helical polarization coiled into another helix, namely a polar superhelix, can be extrinsically stabilized in ferroelectric nanosprings. The interplay between dipolar interactions confined in the chiral geometry and the complex strain field of mixed bending and twisting induces the superhelical configuration of electric polarization. The geometrical structure of the polar superhelix gives rise to electric chiralities at two different length scales and the coexistence of three order parameters, i.e., polarization, toroidization, and hypertoroidization, both of which can be manipulated by homogeneous electric and/or mechanical fields. Our work therefore provides a new geometrical configuration of swirling dipolar fields, which offers the possibility of multiple order-parameters, and electromechanically controllable dipolar chiralities and associated electro-optical responses.
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Affiliation(s)
- Takahiro Shimada
- Department of Mechanical Engineering and Science, Kyoto University, Nishikyo-ku, Kyoto 615-8540, Japan
| | - Le Van Lich
- Department of Mechanical Engineering and Science, Kyoto University, Nishikyo-ku, Kyoto 615-8540, Japan
| | - Koyo Nagano
- Department of Mechanical Engineering and Science, Kyoto University, Nishikyo-ku, Kyoto 615-8540, Japan
| | - Jian-Shan Wang
- Tianjin Key Laboratory of Modern Engineering Mechanics, Department of Mechanics, Tianjin University, Tianjin 300072, China
| | - Jie Wang
- Department of Engineering Mechanics, School of Aeronautics and Astronautics, Zhejiang University, Hangzhou 310027, China
| | - Takayuki Kitamura
- Department of Mechanical Engineering and Science, Kyoto University, Nishikyo-ku, Kyoto 615-8540, Japan
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Wei XK, Jia CL, Sluka T, Wang BX, Ye ZG, Setter N. Néel-like domain walls in ferroelectric Pb(Zr,Ti)O3 single crystals. Nat Commun 2016; 7:12385. [PMID: 27539075 PMCID: PMC4992163 DOI: 10.1038/ncomms12385] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2015] [Accepted: 06/28/2016] [Indexed: 02/03/2023] Open
Abstract
In contrast to the flexible rotation of magnetization direction in ferromagnets, the spontaneous polarization in ferroelectric materials is highly confined along the symmetry-allowed directions. Accordingly, chirality at ferroelectric domain walls was treated only at the theoretical level and its real appearance is still a mystery. Here we report a Néel-like domain wall imaged by atom-resolved transmission electron microscopy in Ti-rich ferroelectric Pb(Zr1−xTix)O3 crystals, where nanometre-scale monoclinic order coexists with the tetragonal order. The formation of such domain walls is interpreted in the light of polarization discontinuity and clamping effects at phase boundaries between the nesting domains. Phase-field simulation confirms that the coexistence of both phases as encountered near the morphotropic phase boundary promotes the polarization to rotate in a continuous manner. Our results provide a further insight into the complex domain configuration in ferroelectrics, and establish a foundation towards exploring chiral domain walls in ferroelectrics. Flexible rotation of spontaneous polarization at ferroelectric domain walls is predicted in theory but lacks evidence from experiment. Here, Wei et al. image a Néel-like domain wall in Ti-rich ferroelectric Pb(Zr1−xTix)O3 crystals, providing insight in exploring chiral domain walls in ferroelectrics.
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Affiliation(s)
- Xian-Kui Wei
- Ceramics Laboratory, EPFL-Swiss Federal Institute of Technology, Lausanne 1015, Switzerland.,Peter Grünberg Institute and Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons, Forschungszentrum Jülich GmbH, 52425 Jülich, Germany
| | - Chun-Lin Jia
- Peter Grünberg Institute and Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons, Forschungszentrum Jülich GmbH, 52425 Jülich, Germany.,The School of Electronic and Information Engineering, Xi'an Jiaotong University, Xi'an 710049, China
| | - Tomas Sluka
- Ceramics Laboratory, EPFL-Swiss Federal Institute of Technology, Lausanne 1015, Switzerland
| | - Bi-Xia Wang
- Department of Chemistry and 4D LABS, Simon Fraser University, 8888 University Drive, Burnaby, British Columbia, Canada V5A 1S6
| | - Zuo-Guang Ye
- Department of Chemistry and 4D LABS, Simon Fraser University, 8888 University Drive, Burnaby, British Columbia, Canada V5A 1S6.,Electronic Materials Research Laboratory, Key Laboratory of the Ministry of Education and International Center for Dielectric Research, Xi'an Jiaotong University, Xi'an 710049, China
| | - Nava Setter
- Ceramics Laboratory, EPFL-Swiss Federal Institute of Technology, Lausanne 1015, Switzerland
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Hong S, Nakhmanson SM, Fong DD. Screening mechanisms at polar oxide heterointerfaces. REPORTS ON PROGRESS IN PHYSICS. PHYSICAL SOCIETY (GREAT BRITAIN) 2016; 79:076501. [PMID: 27308889 DOI: 10.1088/0034-4885/79/7/076501] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
The interfaces of polar oxide heterostructures can display electronic properties unique from the oxides they border, as they require screening from either internal or external sources of charge. The screening mechanism depends on a variety of factors, including the band structure at the interface, the presence of point defects or adsorbates, whether or not the oxide is ferroelectric, and whether or not an external field is applied. In this review, we discuss both theoretical and experimental aspects of different screening mechanisms, giving special emphasis to ways in which the mechanism can be altered to provide novel or tunable functionalities. We begin with a theoretical introduction to the problem and highlight recent progress in understanding the impact of point defects on polar interfaces. Different case studies are then discussed, for both the high thickness regime, where interfaces must be screened and each interface can be considered separately, and the low thickness regime, where the degree and nature of screening can be manipulated and the interfaces are close enough to interact. We end with a brief outlook toward new developments in this rapidly progressing field.
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Affiliation(s)
- Seungbum Hong
- Materials Science Division, Argonne National Laboratory, Argonne, IL 60439, USA. Department of Materials Science & Engineering, KAIST, Daejeon 305-701, Korea
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35
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Observation of polar vortices in oxide superlattices. Nature 2016; 530:198-201. [DOI: 10.1038/nature16463] [Citation(s) in RCA: 537] [Impact Index Per Article: 67.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2015] [Accepted: 11/16/2015] [Indexed: 11/08/2022]
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36
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Evans DM, Alexe M, Schilling A, Kumar A, Sanchez D, Ortega N, Katiyar RS, Scott JF, Gregg JM. The nature of magnetoelectric coupling in Pb(Zr,Ti)O3 -Pb(Fe,Ta)O3. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2015; 27:6068-6073. [PMID: 26351267 DOI: 10.1002/adma.201501749] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2015] [Revised: 06/25/2015] [Indexed: 06/05/2023]
Abstract
The coupling between magnetization and polarization in a room temperature multiferroic (Pb(Zr,Ti)O3 -Pb(Fe,Ta)O3 ) is explored by monitoring the changes in capacitance that occur when a magnetic field is applied in each of three orthogonal directions. Magnetocapacitance effects, consistent with P(2) M(2) coupling, are strongest when fields are applied in the plane of the single crystal sheet investigated.
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Affiliation(s)
- Donald M Evans
- Centre for Nanostructured Media, School of Maths and Physics, Queen's University Belfast, Belfast BT7 1NN, Northern Ireland, UK
| | - Marin Alexe
- Department of Physics, University of Warwick, Coventry, CV4 7AL, UK
| | - Alina Schilling
- Centre for Nanostructured Media, School of Maths and Physics, Queen's University Belfast, Belfast BT7 1NN, Northern Ireland, UK
| | - Ashok Kumar
- National Physical Laboratory, New Delhi, Delhi, 110012, India
| | - Dilsom Sanchez
- Institute for Functional Nanomaterials, University of Puerto Rico, PO Box 23334, San Juan, PR, 00931-3334, USA
| | - Nora Ortega
- Institute for Functional Nanomaterials, University of Puerto Rico, PO Box 23334, San Juan, PR, 00931-3334, USA
| | - Ram S Katiyar
- Institute for Functional Nanomaterials, University of Puerto Rico, PO Box 23334, San Juan, PR, 00931-3334, USA
| | - James F Scott
- School of Chemistry, University of St Andrews, St Andrews, KY16 9ST, Scotland, UK
- School of Physics and Astronomy, University of St Andrews, North Haugh, St Andrews, KY16 9SS, Scotland, UK
| | - J Marty Gregg
- Centre for Nanostructured Media, School of Maths and Physics, Queen's University Belfast, Belfast BT7 1NN, Northern Ireland, UK
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37
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Discovery of stable skyrmionic state in ferroelectric nanocomposites. Nat Commun 2015; 6:8542. [PMID: 26436432 PMCID: PMC4600738 DOI: 10.1038/ncomms9542] [Citation(s) in RCA: 68] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2015] [Accepted: 09/01/2015] [Indexed: 11/08/2022] Open
Abstract
Non-coplanar swirling field textures, or skyrmions, are now widely recognized as objects of both fundamental interest and technological relevance. So far, skyrmions were amply investigated in magnets, where due to the presence of chiral interactions, these topological objects were found to be intrinsically stabilized. Ferroelectrics on the other hand, lacking such chiral interactions, were somewhat left aside in this quest. Here we demonstrate, via the use of a first-principles-based framework, that skyrmionic configuration of polarization can be extrinsically stabilized in ferroelectric nanocomposites. The interplay between the considered confined geometry and the dipolar interaction underlying the ferroelectric phase instability induces skyrmionic configurations. The topological structure of the obtained electrical skyrmion can be mapped onto the topology of domain-wall junctions. Furthermore, the stabilized electrical skyrmion can be as small as a few nanometers, thus revealing prospective skyrmion-based applications of ferroelectric nanocomposites.
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Shimada T, Lich LV, Nagano K, Wang J, Kitamura T. Hierarchical ferroelectric and ferrotoroidic polarizations coexistent in nano-metamaterials. Sci Rep 2015; 5:14653. [PMID: 26424484 PMCID: PMC4589792 DOI: 10.1038/srep14653] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2015] [Accepted: 09/02/2015] [Indexed: 11/25/2022] Open
Abstract
Tailoring materials to obtain unique, or significantly enhanced material properties through rationally designed structures rather than chemical constituents is principle of metamaterial concept, which leads to the realization of remarkable optical and mechanical properties. Inspired by the recent progress in electromagnetic and mechanical metamaterials, here we introduce the concept of ferroelectric nano-metamaterials, and demonstrate through an experiment in silico with hierarchical nanostructures of ferroelectrics using sophisticated real-space phase-field techniques. This new concept enables variety of unusual and complex yet controllable domain patterns to be achieved, where the coexistence between hierarchical ferroelectric and ferrotoroidic polarizations establishes a new benchmark for exploration of complexity in spontaneous polarization ordering. The concept opens a novel route to effectively tailor domain configurations through the control of internal structure, facilitating access to stabilization and control of complex domain patterns that provide high potential for novel functionalities. A key design parameter to achieve such complex patterns is explored based on the parity of junctions that connect constituent nanostructures. We further highlight the variety of additional functionalities that are potentially obtained from ferroelectric nano-metamaterials, and provide promising perspectives for novel multifunctional devices. This study proposes an entirely new discipline of ferroelectric nano-metamaterials, further driving advances in metamaterials research.
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Affiliation(s)
- Takahiro Shimada
- Department of Mechanical Engineering and Science, Kyoto University, Nishikyo-ku, Kyoto 615-8540, Japan
| | - Le Van Lich
- Department of Mechanical Engineering and Science, Kyoto University, Nishikyo-ku, Kyoto 615-8540, Japan
| | - Koyo Nagano
- Department of Mechanical Engineering and Science, Kyoto University, Nishikyo-ku, Kyoto 615-8540, Japan
| | - Jie Wang
- Department of Engineering Mechanics, School of Aeronautics and Astronautics, Zhejiang University, Hangzhou 310027, China
| | - Takayuki Kitamura
- Department of Mechanical Engineering and Science, Kyoto University, Nishikyo-ku, Kyoto 615-8540, Japan
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39
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Pennington RS, Koch CT. A three-dimensional polarization domain retrieval method from electron diffraction data. Ultramicroscopy 2015; 155:42-48. [DOI: 10.1016/j.ultramic.2015.04.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2015] [Revised: 03/31/2015] [Accepted: 04/01/2015] [Indexed: 10/23/2022]
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40
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Gui Z, Wang LW, Bellaiche L. Electronic properties of electrical vortices in ferroelectric nanocomposites from large-scale ab initio computations. NANO LETTERS 2015; 15:3224-3229. [PMID: 25830817 DOI: 10.1021/acs.nanolett.5b00307] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
An original ab initio procedure is developed and applied to a ferroelectric nanocomposite, in order to reveal the effect of electrical vortices on electronic properties. Such procedure involves the combination of two large-scale numerical schemes, namely, the effective Hamiltonian (to incorporate ionic degrees of freedom) and the linear-scaling three-dimensional fragment method (to treat electronic degrees of freedom). The use of such procedure sheds some light into the origin of the recently observed current that is activated at rather low voltages in systems possessing electrical vortices. It also reveals a novel electronic phenomena that is a systematic control of the type of the band-alignment (i.e., type I versus type II) within the same material via the temperature-driven annihilation/formation of electrical topological defects.
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Affiliation(s)
- Zhigang Gui
- †Physics Department and Institute for Nanoscience and Engineering, University of Arkansas, Fayetteville, Arkansas 72701, United States
| | - Lin-Wang Wang
- ‡Materials Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - L Bellaiche
- †Physics Department and Institute for Nanoscience and Engineering, University of Arkansas, Fayetteville, Arkansas 72701, United States
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41
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Tang YL, Zhu YL, Ma XL, Borisevich AY, Morozovska AN, Eliseev EA, Wang WY, Wang YJ, Xu YB, Zhang ZD, Pennycook SJ. Observation of a periodic array of flux-closure quadrants in strained ferroelectric PbTiO3 films. Science 2015; 348:547-51. [DOI: 10.1126/science.1259869] [Citation(s) in RCA: 332] [Impact Index Per Article: 36.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2014] [Accepted: 03/24/2015] [Indexed: 11/02/2022]
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Khan AI, Marti X, Serrao C, Ramesh R, Salahuddin S. Voltage-controlled ferroelastic switching in Pb(Zr0.2Ti0.8)O3 thin films. NANO LETTERS 2015; 15:2229-2234. [PMID: 25734797 DOI: 10.1021/nl503806p] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
We report a voltage controlled reversible creation and annihilation of a-axis oriented ∼10 nm wide ferroelastic nanodomains without a concurrent ferroelectric 180° switching of the surrounding c-domain matrix in archetypal ferroelectric Pb(Zr0.2Ti0.8)O3 thin films by using the piezo-response force microscopy technique. In previous studies, the coupled nature of ferroelectric switching and ferroelastic rotation has made it difficult to differentiate the underlying physics of ferroelastic domain wall movement. Our observation of distinct thresholds for ferroelectric and ferroelastic switching allows us investigate the ferroelastic switching cleanly and demonstrate a new degree of nanoscale control over the ferroelastic domains.
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Affiliation(s)
| | - Xavier Marti
- ⊥Institute of Physics ASCR, v.v.i., Cukrovarnická 10, 162 53 Praha 6, Czech Republic
| | | | - Ramamoorthy Ramesh
- ∥Material Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Sayeef Salahuddin
- ∥Material Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
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43
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Ferroelectric domain wall motion induced by polarized light. Nat Commun 2015; 6:6594. [PMID: 25779918 PMCID: PMC4382678 DOI: 10.1038/ncomms7594] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2014] [Accepted: 02/10/2015] [Indexed: 11/09/2022] Open
Abstract
Ferroelectric materials exhibit spontaneous and stable polarization, which can usually be reoriented by an applied external electric field. The electrically switchable nature of this polarization is at the core of various ferroelectric devices. The motion of the associated domain walls provides the basis for ferroelectric memory, in which the storage of data bits is achieved by driving domain walls that separate regions with different polarization directions. Here we show the surprising ability to move ferroelectric domain walls of a BaTiO3 single crystal by varying the polarization angle of a coherent light source. This unexpected coupling between polarized light and ferroelectric polarization modifies the stress induced in the BaTiO3 at the domain wall, which is observed using in situ confocal Raman spectroscopy. This effect potentially leads to the non-contact remote control of ferroelectric domain walls by light. Domain walls between ferroelectric domains are of interest for ferroelectric memory and to achieve a better control of the switching process. Here, the authors induce the motion of ferroelectric domains by light, creating a new possibility to control ferroelectrics.
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44
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McQuaid RGP, Gruverman A, Scott JF, Gregg JM. Exploring vertex interactions in ferroelectric flux-closure domains. NANO LETTERS 2014; 14:4230-4237. [PMID: 25058751 DOI: 10.1021/nl5006788] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Using piezoresponse force microscopy, we have observed the progressive development of ferroelectric flux-closure domain structures and Landau-Kittel-type domain patterns, in 300 nm thick single-crystal BaTiO3 platelets. As the microstructural development proceeds, the rate of change of the domain configuration is seen to decrease exponentially. Nevertheless, domain wall velocities throughout are commensurate with creep processes in oxide ferroelectrics. Progressive screening of macroscopic destabilizing fields, primarily the surface-related depolarizing field, successfully describes the main features of the observed kinetics. Changes in the separation of domain-wall vertex junctions prompt a consideration that vertex-vertex interactions could be influencing the measured kinetics. However, the expected dynamic signatures associated with direct vertex-vertex interactions are not resolved. If present, our measurements confine the length scale for interaction between vertices to the order of a few hundred nanometers.
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Affiliation(s)
- Raymond G P McQuaid
- School of Mathematics and Physics, Queen's University Belfast , Belfast, BT7 1NN, U.K
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45
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Super switching and control of in-plane ferroelectric nanodomains in strained thin films. Nat Commun 2014; 5:4415. [DOI: 10.1038/ncomms5415] [Citation(s) in RCA: 74] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2013] [Accepted: 06/16/2014] [Indexed: 11/09/2022] Open
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46
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Schiemer J, Carpenter MA, Evans DM, Gregg JM, Schilling A, Arredondo M, Alexe M, Sanchez D, Ortega N, Katiyar RS, Echizen M, Colliver E, Dutton S, Scott JF. Studies of the Room-Temperature Multiferroic Pb(Fe 0.5Ta 0.5) 0.4(Zr 0.53Ti 0.47) 0.6O 3: Resonant Ultrasound Spectroscopy, Dielectric, and Magnetic Phenomena. ADVANCED FUNCTIONAL MATERIALS 2014; 24:2993-3002. [PMID: 25844085 PMCID: PMC4379905 DOI: 10.1002/adfm.201303492] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/11/2013] [Revised: 11/28/2013] [Indexed: 06/04/2023]
Abstract
Recently, lead iron tantalate/lead zirconium titanate (PZTFT) was demonstrated to possess large, but unreliable, magnetoelectric coupling at room temperature. Such large coupling would be desirable for device applications but reproducibility would also be critical. To better understand the coupling, the properties of all 3 ferroic order parameters, elastic, electric, and magnetic, believed to be present in the material across a range of temperatures, are investigated. In high temperature elastic data, an anomaly is observed at the orthorhombic mm2 to tetragonal 4mm transition, Tot = 475 K, and a softening trend is observed as the temperature is increased toward 1300 K, where the material is known to become cubic. Thermal degradation makes it impossible to measure elastic behavior up to this temperature, however. In the low temperature region, there are elastic anomalies near ≈40 K and in the range 160-245 K. The former is interpreted as being due to a magnetic ordering transition and the latter is interpreted as a hysteretic regime of mixed rhombohedral and orthorhombic structures. Electrical and magnetic data collected below room temperature show anomalies at remarkably similar temperature ranges to the elastic data. These observations are used to suggest that the three order parameters in PZTFT are strongly coupled.
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Affiliation(s)
- J Schiemer
- Department of Earth Sciences, University of CambridgeCambridge, CB2 0EQ, UK
| | - M A Carpenter
- Department of Earth Sciences, University of CambridgeCambridge, CB2 0EQ, UK
| | - D M Evans
- School of Mathematics & Physics, Queen's University of BelfastBelfast, BT7 1NN, UK
| | - J M Gregg
- School of Mathematics & Physics, Queen's University of BelfastBelfast, BT7 1NN, UK
| | - A Schilling
- School of Mathematics & Physics, Queen's University of BelfastBelfast, BT7 1NN, UK
| | - M Arredondo
- School of Mathematics & Physics, Queen's University of BelfastBelfast, BT7 1NN, UK
| | - M Alexe
- Max Planck Institute of Microstructure PhysicsWeinberg 2, 06120, Halle (Saale), Germany
| | - D Sanchez
- Institute for Functional Nanomaterials, University of Puerto RicoPO Box 23334, San Juan, 00931–3334, Puerto Rico
| | - N Ortega
- Institute for Functional Nanomaterials, University of Puerto RicoPO Box 23334, San Juan, 00931–3334, Puerto Rico
| | - R S Katiyar
- Institute for Functional Nanomaterials, University of Puerto RicoPO Box 23334, San Juan, 00931–3334, Puerto Rico
| | - M Echizen
- Cavendish Laboratory, University of CambridgeMadingley Road, Cambridge, CB3 0HE, UK
| | - E Colliver
- Cavendish Laboratory, University of CambridgeMadingley Road, Cambridge, CB3 0HE, UK
| | - S Dutton
- Cavendish Laboratory, University of CambridgeMadingley Road, Cambridge, CB3 0HE, UK
| | - J F Scott
- Cavendish Laboratory, University of CambridgeMadingley Road, Cambridge, CB3 0HE, UK
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Abstract
Here we present a simple and fast method to reliably image polarization charges using charge gradient microscopy (CGM). We collected the current from the grounded CGM probe while scanning a periodically poled lithium niobate single crystal and single-crystal LiTaO3 thin film on the Cr electrode. We observed current signals at the domains and domain walls originating from the displacement current and the relocation or removal of surface charges, which enabled us to visualize the ferroelectric domains at a scan frequency above 78 Hz over 10 μm. We envision that CGM can be used in high-speed ferroelectric domain imaging and piezoelectric energy-harvesting devices.
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48
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Szwarcman D, Prosandeev S, Louis L, Berger S, Rosenberg Y, Lereah Y, Bellaiche L, Markovich G. The stabilization of a single domain in free-standing ferroelectric nanocrystals. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2014; 26:122202. [PMID: 24594615 DOI: 10.1088/0953-8984/26/12/122202] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
High resolution electron microscopy, electron diffraction and electron holography were used to study individual free-standing ∼ 30 nm barium titanate nanocrystals. Large unidirectional variations in the tetragonal distortion were mapped across the smaller nanocrystals, peaking to anomalously large values of up to 4% at the centers of the nanocrystals. This indicated that the nanocrystals consist of highly strained single ferroelectric domains. Simulations using an effective Hamiltonian for modeling a nanocrystal under a small depolarizing field and negative pressure qualitatively confirm this picture. These simulations, along with the development of a phenomenological model, show that the tetragonal distortion variation is a combined effect of: (i) electrostrictive coupling between the spontaneous polarization and strain inside the nanocrystal, and (ii) a surface-induced effective stress existing inside the nanodot. As a result, a 'strain skin layer', having a smaller tetragonal distortion relative to the core of the nanocrystal, is created.
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Affiliation(s)
- Daniel Szwarcman
- Department of Chemical Physics, School of Chemistry, Raymond and Beverly Sackler Faculty of Exact Sciences, Tel-Aviv University, Tel-Aviv 69978, Israel
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49
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Sodani PR, Sharma K. A study on patient satisfaction at a multi super specialty hospital in Delhi. Hosp Top 2014; 92:1-6. [PMID: 24621132 DOI: 10.1080/00185868.2014.875311] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
The main objective of the study was to assess the level of satisfaction in terms of various quality dimensions among the patients in the study hospital. Data were collected from inpatients through structured questionnaire on eight quality dimensions such as general satisfaction, technical quality, interpersonal manner, communication, financial aspects, time spent with doctors, accessibility and convenience, and hospital services. In total, 100 inpatients were included from three departments with highest patient inflow: medicine, gynecology, and surgery. Most of the respondents were male and belongs to the age group of 31-45 years. Findings depict that highest level of satisfaction was found for interpersonal manner (86.3%) followed by communication (85.4%), general satisfaction (79.3%), and technical quality (77.3%). Least level of satisfaction was found for financial aspects (61.6%), followed by hospital services (68%), accessibility and convenience (73.5%), and time spent with doctor (76.9%).
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50
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Evans DM, Schilling A, Kumar A, Sanchez D, Ortega N, Katiyar RS, Scott JF, Gregg JM. Switching ferroelectric domain configurations using both electric and magnetic fields in Pb(Zr,Ti)O3-Pb(Fe,Ta)O3 single-crystal lamellae. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2014; 372:20120450. [PMID: 24421376 PMCID: PMC3895977 DOI: 10.1098/rsta.2012.0450] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Thin single-crystal lamellae cut from Pb(Zr,Ti)O3-Pb(Fe,Ta)O3 ceramic samples have been integrated into simple coplanar capacitor devices. The influence of applied electric and magnetic fields on ferroelectric domain configurations has been mapped, using piezoresponse force microscopy. The extent to which magnetic fields alter the ferroelectric domains was found to be strongly history dependent: after switching had been induced by applying electric fields, the susceptibility of the domains to change under a magnetic field (the effective magnetoelectric coupling parameter) was large. Such large, magnetic field-induced changes resulted in a remanent domain state very similar to the remanent state induced by an electric field. Subsequent magnetic field reversal induced more modest ferroelectric switching.
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Affiliation(s)
- D. M. Evans
- School of Mathematics and Physics, Queen's University Belfast, Belfast BT7 1NN, UK
| | - A. Schilling
- School of Mathematics and Physics, Queen's University Belfast, Belfast BT7 1NN, UK
| | - Ashok Kumar
- Department of Physics and Institute of Multifunctional Materials, University of Puerto Rico, San Juan, PR 00931, USA
- Materials Physics and Engineering Division, National Physical Laboratory, New Delhi 110012, India
| | - D. Sanchez
- Department of Physics and Institute of Multifunctional Materials, University of Puerto Rico, San Juan, PR 00931, USA
| | - N. Ortega
- Department of Physics and Institute of Multifunctional Materials, University of Puerto Rico, San Juan, PR 00931, USA
| | - R. S. Katiyar
- Department of Physics and Institute of Multifunctional Materials, University of Puerto Rico, San Juan, PR 00931, USA
| | - J. F. Scott
- Department of Physics, Cavendish Laboratory, J. J. Thomson Avenue, Cambridge CB3 0HE, UK
| | - J. M. Gregg
- School of Mathematics and Physics, Queen's University Belfast, Belfast BT7 1NN, UK
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