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Li T, Deng S, Liu H, Chen J. Insights into Strain Engineering: From Ferroelectrics to Related Functional Materials and Beyond. Chem Rev 2024; 124:7045-7105. [PMID: 38754042 DOI: 10.1021/acs.chemrev.3c00767] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/18/2024]
Abstract
Ferroelectrics have become indispensable components in various application fields, including information processing, energy harvesting, and electromechanical conversion, owing to their unique ability to exhibit electrically or mechanically switchable polarization. The distinct polar noncentrosymmetric lattices of ferroelectrics make them highly responsive to specific crystal structures. Even slight changes in the lattice can alter the polarization configuration and response to external fields. In this regard, strain engineering has emerged as a prevalent regulation approach that not only offers a versatile platform for structural and performance optimization within ferroelectrics but also unlocks boundless potential in various functional materials. In this review, we systematically summarize the breakthroughs in ferroelectric-based functional materials achieved through strain engineering and progress in method development. We cover research activities ranging from fundamental attributes to wide-ranging applications and novel functionalities ranging from electromechanical transformation in sensors and actuators to tunable dielectric materials and information technologies, such as transistors and nonvolatile memories. Building upon these achievements, we also explore the endeavors to uncover the unprecedented properties through strain engineering in related chemical functionalities, such as ferromagnetism, multiferroicity, and photoelectricity. Finally, through discussions on the prospects and challenges associated with strain engineering in the materials, this review aims to stimulate the development of new methods for strain regulation and performance boosting in functional materials, transcending the boundaries of ferroelectrics.
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Affiliation(s)
- Tianyu Li
- Department of Physical Chemistry, University of Science and Technology Beijing, Beijing 100083, China
- Beijing Advanced Innovation Center for Materials Genome Engineering, University of Science and Technology Beijing, Beijing 100083, China
| | - Shiqing Deng
- Beijing Advanced Innovation Center for Materials Genome Engineering, University of Science and Technology Beijing, Beijing 100083, China
| | - Hui Liu
- Beijing Advanced Innovation Center for Materials Genome Engineering, University of Science and Technology Beijing, Beijing 100083, China
| | - Jun Chen
- Department of Physical Chemistry, University of Science and Technology Beijing, Beijing 100083, China
- Beijing Advanced Innovation Center for Materials Genome Engineering, University of Science and Technology Beijing, Beijing 100083, China
- Hainan University, Haikou 570228, China
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2
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Yang W, Cheng B, Hou J, Deng J, Ding X, Sun J, Liu JZ. Writing-Speed Dependent Thresholds of Ferroelectric Domain Switching in Monolayer α-In 2 Se 3. SMALL METHODS 2023; 7:e2300050. [PMID: 37144659 DOI: 10.1002/smtd.202300050] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/13/2023] [Revised: 03/19/2023] [Indexed: 05/06/2023]
Abstract
An electrical-biased or mechanical-loaded scanning probe written on the ferroelectric surface can generate programmable domain nanopatterns for ultra-scaled and reconfigurable nanoscale electronics. Fabricating ferroelectric domain patterns by direct-writing as quickly as possible is highly desirable for high response rate devices. Using monolayer α-In2 Se3 ferroelectric with ≈1.2 nm thickness and intrinsic out-of-plane polarization as an example, a writing-speed dependent effect on ferroelectric domain switching is discovered. The results indicate that the threshold voltages and threshold forces for domain switching can be increased from -4.2 to -5 V and from 365 to 1216 nN, respectively, as the writing-speed increases from 2.2 to 10.6 µm s-1 . The writing-speed dependent threshold voltages can be attributed to the nucleations of reoriented ferroelectric domains, in which sufficient time is needed for subsequent domain growth. The writing-speed dependent threshold forces can be attributed to the flexoelectric effect. Furthermore, the electrical-mechanical coupling can be employed to decrease the threshold force, achieving as low as ≈189±41 nN, a value smaller than those of perovskite ferroelectric films. Such findings reveal a critical issue of ferroelectric domain pattern engineering that should be carefully addressed for programmable direct-writing electronics applications.
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Affiliation(s)
- Weijie Yang
- State Key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong University, Xi'an, 710049, China
| | - Bo Cheng
- State Key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong University, Xi'an, 710049, China
| | - Jianhua Hou
- State Key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong University, Xi'an, 710049, China
| | - Junkai Deng
- State Key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong University, Xi'an, 710049, China
| | - Xiangdong Ding
- State Key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong University, Xi'an, 710049, China
| | - Jun Sun
- State Key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong University, Xi'an, 710049, China
| | - Jefferson Zhe Liu
- Department of Mechanical Engineering, The University of Melbourne, Parkville, VIC, 3010, Australia
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3
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Liu M, Tian Y, Liu Z. A Strategy to Enhance the Ferroelectric Behavior of MOF-802(Hf) via Doping Zr 4+ Ions. Inorg Chem 2023; 62:8285-8292. [PMID: 37184903 DOI: 10.1021/acs.inorgchem.3c00760] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
MOF ferroelectrics, as a crucial member of molecular ferroelectrics, have shown intriguing advantages owing to the designability of structures and tunability of physicochemical properties, which make them an appealing group of ferroelectric materials. However, the weak ferroelectric property still is a huge challenge for further development. Here, a series of Zr-doped MOF-802(Hf)s were successfully synthesized through doping Zr4+ ions into the parent MOF-802(Hf) to improve ferroelectric properties. The well-shaped P-E hysteresis loops of Zr-doped MOF-802(Hf)s illustrate their ferroelectricity, and ferroelectric properties are effectively enhanced compared with the parent MOF-802(Hf). What's more, remanent polarization reaches 0.511 μC/cm2 when the concentration of Zr4+ ions is 5%, which is 5 times higher than that of the parent MOF-802(Hf) and is on par with some perovskite ferroelectrics. The increased ferroelectric performance is attributed to the enhanced polarity of the whole structure triggered by lattice distortion when Hf4+ ions of the parent MOF-802(Hf) are substituted by Zr4+ ions. As far as we know, this is the first report on Hf-MOF exhibiting improved ferroelectric behaviors through doping metal ions into lattice nodes. This work demonstrates that introducing the second metal ions into lattice nodes of MOFs is an efficacious approach for exploiting MOF ferroelectrics with superior performance.
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Affiliation(s)
- Meiying Liu
- Inner Mongolia Key Laboratory of Chemistry and Physics of Rare Earth Materials, School of Chemistry and Chemical Engineering, Inner Mongolia University, Hohhot 010021, P.R. China
| | - Yadong Tian
- Inner Mongolia Key Laboratory of Chemistry and Physics of Rare Earth Materials, School of Chemistry and Chemical Engineering, Inner Mongolia University, Hohhot 010021, P.R. China
| | - Zhiliang Liu
- Inner Mongolia Key Laboratory of Chemistry and Physics of Rare Earth Materials, School of Chemistry and Chemical Engineering, Inner Mongolia University, Hohhot 010021, P.R. China
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4
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Liu M, Tian Y, Liu Z. Effective Enhancement of the Ferroelectric Performance of Polar Co-Gallate MOF by Doping M 2+ Ions (M = Mg, Mn, Ni) into Framework Nodes. Inorg Chem 2023; 62:7024-7031. [PMID: 37120854 DOI: 10.1021/acs.inorgchem.3c00300] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
MOF ferroelectrics have been demonstrated to be a promising candidate owing to various structures and controllable properties. However, weak ferroelectricity hampers their boom. Herein, a convenient strategy, doping metal ions into the framework nodes of parent MOF, is adopted to enhance ferroelectric performance. A series of M-doped Co-Gallate (M = Mg, Mn, Ni) were synthesized to improve ferroelectric properties. The electrical hysteresis loop demonstrated its ferroelectric behaviors, exhibiting obviously improved ferroelectric properties compared with the parent Co-Gallate. The remanent polarization was enhanced by two times for Mg-doped Co-Gallate, six times for Mn-doped Co-Gallate, and four times for Ni-doped Co-Gallate. The promoted ferroelectric performances are ascribed to the enhanced polarity of the overall structure triggered by framework distortion. Intriguingly, ferroelectric behaviors increase in the order Mg < Ni < Mn, displaying the same tendency as the difference value in the ionic radius between Co2+ ions and M2+ metal ions (M = Mg, Mn, Ni). These results demonstrate doping of metal ions is a valid strategy to enhance ferroelectric performances, which may serve as a guide in modulating ferroelectric behaviors.
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Affiliation(s)
- Meiying Liu
- Inner Mongolia Key Laboratory of Chemistry and Physics of Rare Earth Materials, School of Chemistry and Chemical Engineering, Inner Mongolia University, Hohhot 010021, P. R. China
| | - Yadong Tian
- Inner Mongolia Key Laboratory of Chemistry and Physics of Rare Earth Materials, School of Chemistry and Chemical Engineering, Inner Mongolia University, Hohhot 010021, P. R. China
| | - Zhiliang Liu
- Inner Mongolia Key Laboratory of Chemistry and Physics of Rare Earth Materials, School of Chemistry and Chemical Engineering, Inner Mongolia University, Hohhot 010021, P. R. China
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5
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Spasojevic I, Santiso J, Caicedo JM, Catalan G, Domingo N. Tunable Molecular Electrodes for Bistable Polarization Screening. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2023:e2207799. [PMID: 37066721 DOI: 10.1002/smll.202207799] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Revised: 02/27/2023] [Indexed: 06/19/2023]
Abstract
The polar discontinuity at any ferroelectric surface creates a depolarizing field that must be screened for the polarization to be stable. In capacitors, screening is done by the electrodes, while in bare ferroelectric surfaces it is typically accomplished by atmospheric adsorbates. Although chemisorbed species can have even better screening efficiency than conventional electrodes, they are subject to unpredictable environmental fluctuations and, moreover, dominant charged species favor one polarity over the opposite. This paper proposes a new screening concept, namely surface functionalization with resonance-hybrid molecules, which combines the predictability and bipolarity of conventional electrodes with the screening efficiency of adsorbates. Thin films of barium titanate (BaTiO3 ) coated with resonant para-aminobenzoic acid (pABA) display increased coercivity for both signs of ferroelectric polarization irrespective of the molecular layer thickness, thanks to the ability of these molecules to swap between different electronic configurations and adapt their surface charge density to the screening needs of the ferroelectric underneath. Because electron delocalization is only in the vertical direction, unlike conventional metals, chemical electrodes allow writing localized domains of different polarity underneath the same electrode. In addition, hybrid capacitors composed of graphene/pABA/ferroelectric have been made with enhanced coercivity compared to pure graphene-electode capacitors.
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Affiliation(s)
- Irena Spasojevic
- Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and BIST, Campus UAB, Bellaterra, Barcelona, 08193, Spain
- Department of Chemistry, Universitat Autònoma de Barcelona, Bellaterra, Barcelona, 08193, Spain
| | - José Santiso
- Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and BIST, Campus UAB, Bellaterra, Barcelona, 08193, Spain
| | - José Manuel Caicedo
- Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and BIST, Campus UAB, Bellaterra, Barcelona, 08193, Spain
| | - Gustau Catalan
- Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and BIST, Campus UAB, Bellaterra, Barcelona, 08193, Spain
- ICREA- Institució Catalana de Recerca i Estudis Avançats, Catalonia, Barcelona, 08010, Catalonia
| | - Neus Domingo
- Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and BIST, Campus UAB, Bellaterra, Barcelona, 08193, Spain
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6
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Schultheiß J, Xue F, Roede E, Ånes HW, Danmo FH, Selbach SM, Chen LQ, Meier D. Confinement-Driven Inverse Domain Scaling in Polycrystalline ErMnO 3. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2022; 34:e2203449. [PMID: 36084267 DOI: 10.1002/adma.202203449] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/16/2022] [Revised: 08/17/2022] [Indexed: 06/15/2023]
Abstract
The research on topological phenomena in ferroelectric materials has revolutionized the way people understand polar order. Intriguing examples are polar skyrmions, vortex/anti-vortex structures, and ferroelectric incommensurabilties, which promote emergent physical properties ranging from electric-field-controllable chirality to negative capacitance effects. Here, the impact of topologically protected vortices on the domain formation in improper ferroelectric ErMnO3 polycrystals is studied, demonstrating inverted domain scaling behavior compared to classical ferroelectrics. It is observed that as the grain size increases, smaller domains are formed. Phase field simulations reveal that elastic strain fields drive the annihilation of vortex/anti-vortex pairs within the grains and individual vortices at the grain boundaries. The inversion of the domain scaling behavior has far-reaching implications, providing fundamentally new opportunities for topology-based domain engineering and the tuning of the electromechanical and dielectric performance of ferroelectrics in general.
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Affiliation(s)
- Jan Schultheiß
- Department of Materials Science and Engineering, NTNU Norwegian University of Science and Technology, Høgskoleringen 1, Trondheim, 7034, Norway
| | - Fei Xue
- Department of Materials Science and Engineering, The Pennsylvania State University, University Park, PA, 16802, USA
| | - Erik Roede
- Department of Materials Science and Engineering, NTNU Norwegian University of Science and Technology, Høgskoleringen 1, Trondheim, 7034, Norway
| | - Håkon W Ånes
- Department of Materials Science and Engineering, NTNU Norwegian University of Science and Technology, Høgskoleringen 1, Trondheim, 7034, Norway
| | - Frida H Danmo
- Department of Materials Science and Engineering, NTNU Norwegian University of Science and Technology, Høgskoleringen 1, Trondheim, 7034, Norway
| | - Sverre M Selbach
- Department of Materials Science and Engineering, NTNU Norwegian University of Science and Technology, Høgskoleringen 1, Trondheim, 7034, Norway
| | - Long-Qing Chen
- Department of Materials Science and Engineering, The Pennsylvania State University, University Park, PA, 16802, USA
| | - Dennis Meier
- Department of Materials Science and Engineering, NTNU Norwegian University of Science and Technology, Høgskoleringen 1, Trondheim, 7034, Norway
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7
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Luo ZD, Yang MM, Liu Y, Alexe M. Emerging Opportunities for 2D Semiconductor/Ferroelectric Transistor-Structure Devices. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2021; 33:e2005620. [PMID: 33577112 DOI: 10.1002/adma.202005620] [Citation(s) in RCA: 38] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/19/2020] [Revised: 09/26/2020] [Indexed: 06/12/2023]
Abstract
Semiconductor technology, which is rapidly evolving, is poised to enter a new era for which revolutionary innovations are needed to address fundamental limitations on material and working principle level. 2D semiconductors inherently holding novel properties at the atomic limit show great promise to tackle challenges imposed by traditional bulk semiconductor materials. Synergistic combination of 2D semiconductors with functional ferroelectrics further offers new working principles, and is expected to deliver massively enhanced device performance for existing complementary metal-oxide-semiconductor (CMOS) technologies and add unprecedented applications for next-generation electronics. Herein, recent demonstrations of novel device concepts based on 2D semiconductor/ferroelectric heterostructures are critically reviewed covering their working mechanisms, device construction, applications, and challenges. In particular, emerging opportunities of CMOS-process-compatible 2D semiconductor/ferroelectric transistor structure devices for the development of a rich variety of applications are discussed, including beyond-Boltzmann transistors, nonvolatile memories, neuromorphic devices, and reconfigurable nanodevices such as p-n homojunctions and self-powered photodetectors. It is concluded that 2D semiconductor/ferroelectric heterostructures, as an emergent heterogeneous platform, could drive many more exciting innovations for modern electronics, beyond the capability of ubiquitous silicon systems.
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Affiliation(s)
- Zheng-Dong Luo
- Department of Physics, The University of Warwick, Coventry, CV4 7AL, UK
| | - Ming-Min Yang
- Center for Emergent Matter Science, RIKEN, Wako, Saitama, 351-0198, Japan
| | - Yang Liu
- Department of Materials Science and Engineering, The Pennsylvania State University, University Park, PA, 16802, USA
| | - Marin Alexe
- Department of Physics, The University of Warwick, Coventry, CV4 7AL, UK
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8
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Li Q, Wang B, He Q, Yu P, Chen LQ, Kalinin SV, Li JF. Ferroelastic Nanodomain-mediated Mechanical Switching of Ferroelectricity in Thick Epitaxial Films. NANO LETTERS 2021; 21:445-452. [PMID: 33264026 DOI: 10.1021/acs.nanolett.0c03875] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Mechanical switching of ferroelectric polarization, typically realized via a scanning probe, holds promise in (multi)ferroic device applications. Whereas strain gradient-associated flexoelectricity has been regarded to be accountable for mechanical switching in ultrathin (<10 nm) films, such mechanism can hardly be extended to thicker materials due to intrinsic short operating lengths of flexoelectricity. Here, we demonstrate robust mechanical switching in ∼100 nm thick Pb(Zr0.2Ti0.8)O3 epitaxial films with a characteristic microstructure consisting of nanosized ferroelastic domains. Through a combination of multiscale structural characterizations, piezoresponse force microscopy, and phase-field simulations, we reveal that the ferroelastic nanodomains effectively mediate the 180° switching nucleation in a dynamical manner during tip scanning. Coupled with microstructure engineering, this newly revealed mechanism could boost the utility of mechanical switching through extended material systems. Our results also provide insight into competing polarization switching pathways in complex ferroelectric materials, essential for understanding their electromechanical response.
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Affiliation(s)
- Qian Li
- State Key Laboratory of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing 100084, China
- Center for Nanophase Materials Science, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - Bo Wang
- Department of Materials Science and Engineering, Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Qian He
- Department of Materials Science and Engineering, National University of Singapore, Singapore 119077
| | - Pu Yu
- State Key Laboratory of Low Dimensional Quantum Physics and Department of Physics, Tsinghua University, Beijing 100084, China
| | - Long-Qing Chen
- Department of Materials Science and Engineering, Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Sergei V Kalinin
- Center for Nanophase Materials Science, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - Jing-Feng Li
- State Key Laboratory of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing 100084, China
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9
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Chaudhary P, Lu H, Lipatov A, Ahmadi Z, McConville JPV, Sokolov A, Shield JE, Sinitskii A, Gregg JM, Gruverman A. Low-Voltage Domain-Wall LiNbO 3 Memristors. NANO LETTERS 2020; 20:5873-5878. [PMID: 32574058 DOI: 10.1021/acs.nanolett.0c01836] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Application of conducting ferroelectric domain walls (DWs) as functional elements may facilitate development of conceptually new resistive switching devices. In a conventional approach, several orders of magnitude change in resistance can be achieved by controlling the DW density using supercoercive voltage. However, a deleterious characteristic of this approach is high-energy cost of polarization reversal due to high leakage current. Here, we demonstrate a new approach based on tuning the conductivity of DWs themselves rather than on domain rearrangement. Using LiNbO3 capacitors with graphene, we show that resistance of a device set to a polydomain state can be continuously tuned by application of subcoercive voltage. The tuning mechanism is based on the reversible transition between the conducting and insulating states of DWs. The developed approach allows an energy-efficient control of resistance without the need for domain structure modification. The developed memristive devices are promising for multilevel memories and neuromorphic computing applications.
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Affiliation(s)
- P Chaudhary
- Department of Physics and Astronomy, University of Nebraska, Lincoln, Nebraska 68588, United States
| | - H Lu
- Department of Physics and Astronomy, University of Nebraska, Lincoln, Nebraska 68588, United States
| | - A Lipatov
- Department of Chemistry, University of Nebraska, Lincoln, Nebraska 68588, United States
| | - Z Ahmadi
- Department of Mechanical & Materials Engineering, University of Nebraska, Lincoln, Nebraska 68588, United States
| | - J P V McConville
- Centre for Nanostructured Media, School of Mathematics and Physics, Queen's University Belfast, Belfast BT7 1NN, U.K
| | - A Sokolov
- Department of Physics and Astronomy, University of Nebraska, Lincoln, Nebraska 68588, United States
| | - J E Shield
- Department of Mechanical & Materials Engineering, University of Nebraska, Lincoln, Nebraska 68588, United States
| | - A Sinitskii
- Department of Chemistry, University of Nebraska, Lincoln, Nebraska 68588, United States
| | - J M Gregg
- Centre for Nanostructured Media, School of Mathematics and Physics, Queen's University Belfast, Belfast BT7 1NN, U.K
| | - A Gruverman
- Department of Physics and Astronomy, University of Nebraska, Lincoln, Nebraska 68588, United States
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10
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Kang KT, Park J, Suh D, Choi WS. Synergetic Behavior in 2D Layered Material/Complex Oxide Heterostructures. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2019; 31:e1803732. [PMID: 30589101 DOI: 10.1002/adma.201803732] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2018] [Revised: 09/18/2018] [Indexed: 05/28/2023]
Abstract
The marriage between a 2D layered material (2DLM) and a complex transition metal oxide (TMO) results in a variety of physical and chemical phenomena that cannot be achieved in either material alone. Interesting recent discoveries in systems such as graphene/SrTiO3 , graphene/LaAlO3 /SrTiO3 , graphene/ferroelectric oxide, MoS2 /SrTiO3 , and FeSe/SrTiO3 heterostructures include voltage scaling in field-effect transistors, charge state coupling across an interface, quantum conductance probing of the electrochemical activity, novel memory functions based on charge traps, and greatly enhanced superconductivity. In this context, various properties and functionalities appearing in numerous different 2DLM/TMO heterostructure systems are reviewed. The results imply that the multidimensional heterostructure approach based on the disparate material systems leads to an entirely new platform for the study of condensed matter physics and materials science. The heterostructures are also highly relevant technologically as each constituent material is a promising candidate for next-generation optoelectronic devices.
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Affiliation(s)
- Kyeong Tae Kang
- Department of Physics, Sungkyunkwan University, Suwon, 16419, Korea
| | - Jeongmin Park
- Department of Energy Sciences, Sungkyunkwan University, Suwon, 16419, Korea
| | - Dongseok Suh
- Department of Energy Sciences, Sungkyunkwan University, Suwon, 16419, Korea
| | - Woo Seok Choi
- Department of Physics, Sungkyunkwan University, Suwon, 16419, Korea
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11
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Zafar Z, Zafar A, Wang WH, Liu MY, Ni ZH, You YM. Nonvolatile Memory Based on Molecular Ferroelectric/Graphene Field Effect Transistor. ACS APPLIED MATERIALS & INTERFACES 2018; 10:39187-39193. [PMID: 30295018 DOI: 10.1021/acsami.8b12768] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Ferroelectric thin films are extensively attractive as next-generation nonvolatile memories. Recently, molecular ferroelectrics (MFe), as an emerging new class, have been a new research focus because of their desirable characteristics such as good solution processability, tunable chemical properties, and bio-friendly compositions. However, traditional uniaxial MFe only possess one polar axis which greatly limits their application, as it requires restricted orientational control in single crystal. To achieve macroscopic ferroelectricity and thus fully realize technological advantages of MFe, development of multiaxes is imperative to maximize effective polarization in specific crystallographic orientations. Herein, we present an early exploration on polycrystalline multiaxial MFe thin films of [Hdabco][ReO4] with a two-dimensional graphene hybrid nonvolatile memory device. The polarization switching of MFe is experimentally realized by the nonvolatile modulation of two current states in graphene. Such a hybrid device can exhibit large memory window ∼35 V implying its great potential in memory applications. Hence, by taking the advantages of multiple polarization axes of MFe, the low cost and large area MFe/graphene hybrid memory manifests new possibilities for the integration of these materials as flexible next generation memory devices.
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Affiliation(s)
- Zainab Zafar
- Ordered Matter Science Research Center , Southeast University , Nanjing 211189 , P. R. China
| | - Amina Zafar
- School of Physics , Southeast University , Nanjing 211189 , China
| | - Wen-Hui Wang
- School of Physics , Southeast University , Nanjing 211189 , China
| | - Mei-Ying Liu
- Ordered Matter Science Research Center , Southeast University , Nanjing 211189 , P. R. China
| | - Zhen-Hua Ni
- School of Physics , Southeast University , Nanjing 211189 , China
| | - Yu-Meng You
- Ordered Matter Science Research Center , Southeast University , Nanjing 211189 , P. R. China
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12
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Kang S, Jeon S, Kim S, Seol D, Yang H, Lee J, Kim Y. Tunable Out-of-Plane Piezoelectricity in Thin-Layered MoTe 2 by Surface Corrugation-Mediated Flexoelectricity. ACS APPLIED MATERIALS & INTERFACES 2018; 10:27424-27431. [PMID: 30022658 DOI: 10.1021/acsami.8b06325] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Piezoelectricity crystallographically exists only in the in-plane direction in two-dimensional transition metal dichalcogenides. Here, we demonstrated flexoelectricity-tunable out-of-plane piezoelectricity in semiconducting 2H-MoTe2 flakes by creating surface corrugation. In particular, the strong out-of-plane piezoelectricity and its spatial variation depending on local flexoelectricity was observed even though crystallographically there exists only in-plane piezoelectricity. Surface corrugation-mediated flexoelectricity tuning can be applied to other two-dimensional or thin-layered materials and, furthermore, the results could provide useful information on the interweaving nature between mechanical stimulus and electric dipole in low-dimensional materials.
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Affiliation(s)
| | - Sera Jeon
- Department of Physics , Pusan National University , Busan 46241 , Republic of Korea
| | | | | | | | - Jaekwang Lee
- Department of Physics , Pusan National University , Busan 46241 , Republic of Korea
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13
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Alsubaie A, Sharma P, Lee JH, Kim JY, Yang CH, Seidel J. Uniaxial Strain-Controlled Ferroelastic Domain Evolution in BiFeO 3. ACS APPLIED MATERIALS & INTERFACES 2018; 10:11768-11775. [PMID: 29557167 DOI: 10.1021/acsami.8b01711] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
We investigate the effect of variable uniaxial tensile strain on the evolution of 71° ferroelastic domains in (001)-oriented epitaxial BiFeO3 (BFO) thin films using piezoresponse force microscopy (PFM). For this purpose, a newly designed bending stage has been employed, which allows tensile bending as wells as in situ PFM characterization. In situ PFM imaging reveals polarization-strain correlations at the nanoscale. Specifically, ferroelastic domains with in-plane polarization along the direction of applied tensile strain expand, whereas the adjoining domains with orthogonal in-plane polarization contract. The switching is mediated by significant domain wall roughening and opposite displacement of the successive walls. Further, the domains with long-range order are more susceptible to an applied external mechanical stimulus compared to the domains, which exhibit short-range periodicity. In addition, the imprint state of film reverses direction under applied tensile strain. Finally, the strain-induced changes in the domain structure and wall motion are fully reversible and revert to their as-grown state upon release of the applied stress. The strain-induced non-180° polarization rotation constitutes a route to control connected functionalities, such as magnetism, via coupled in-plane rotation of the magnetic plane in multiferroic BFO thin films.
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Affiliation(s)
- Abdullah Alsubaie
- School of Materials Science and Engineering , UNSW Sydney , Sydney , NSW 2052 , Australia
- School of Physics , Taif University , Taif 26571 , Kingdom of Saudi Arabia
| | - Pankaj Sharma
- School of Materials Science and Engineering , UNSW Sydney , Sydney , NSW 2052 , Australia
| | - Jin Hong Lee
- Unité Mixte de Physique , CNRS, Thales, Université Paris Sud, Université Paris-Saclay , 91767 Palaiseau , France
| | | | | | - Jan Seidel
- School of Materials Science and Engineering , UNSW Sydney , Sydney , NSW 2052 , Australia
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Chen HC, Liu YC. Creating functional water by treating excited gold nanoparticles for the applications of green chemistry, energy and medicine: A review. J IND ENG CHEM 2018. [DOI: 10.1016/j.jiec.2017.09.026] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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Lu H, Lee D, Klyukin K, Tao L, Wang B, Lee H, Lee J, Paudel TR, Chen LQ, Tsymbal EY, Alexandrov V, Eom CB, Gruverman A. Tunneling Hot Spots in Ferroelectric SrTiO 3. NANO LETTERS 2018; 18:491-497. [PMID: 29236501 DOI: 10.1021/acs.nanolett.7b04444] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Strontium titanate (SrTiO3) is the "silicon" in the emerging field of oxide electronics. While bulk properties of this material have been studied for decades, new unexpected phenomena have recently been discovered at the nanoscale, when SrTiO3 forms an ultrathin film or an atomically sharp interface with other materials. One of the striking discoveries is room-temperature ferroelectricity in strain-free ultrathin films of SrTiO3 driven by the TiSr antisite defects, which generate a local dipole moment polarizing the surrounding nanoregion. Here, we demonstrate that these polar defects are not only responsible for ferroelectricity, but also propel the appearance of highly conductive channels, "hot spots", in the ultrathin SrTiO3 films. Using a combination of scanning probe microscopy experimental studies and theoretical modeling, we show that the hot spots emerge due to resonant tunneling through localized electronic states created by the polar defects and that the tunneling conductance of the hot spots is controlled by ferroelectric polarization. Our finding of the polarization-controlled defect-assisted tunneling reveals a new mechanism of resistive switching in oxide heterostructures and may have technological implications for ferroelectric tunnel junctions. It is also shown that the conductivity of the hot spots can be modulated by mechanical stress, opening a possibility for development of conceptually new electronic devices with mechanically tunable resistive states.
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Affiliation(s)
- Haidong Lu
- Department of Physics and Astronomy, University of Nebraska , Lincoln, Nebraska 68588, United States
| | - Daesu Lee
- Department of Materials Science and Engineering, University of Wisconsin-Madison , Madison, Wisconsin 53706, United States
| | - Konstantin Klyukin
- Department of Chemical and Biomolecular Engineering, University of Nebraska , Lincoln, Nebraska 68588, United States
| | - Lingling Tao
- Department of Physics and Astronomy, University of Nebraska , Lincoln, Nebraska 68588, United States
| | - Bo Wang
- Department of Materials Science and Engineering, Pennsylvania State University , University Park, Pennsylvania 16802, United States
| | - Hyungwoo Lee
- Department of Materials Science and Engineering, University of Wisconsin-Madison , Madison, Wisconsin 53706, United States
| | - Jungwoo Lee
- Department of Materials Science and Engineering, University of Wisconsin-Madison , Madison, Wisconsin 53706, United States
| | - Tula R Paudel
- Department of Physics and Astronomy, University of Nebraska , Lincoln, Nebraska 68588, United States
| | - Long-Qing Chen
- Department of Materials Science and Engineering, Pennsylvania State University , University Park, Pennsylvania 16802, United States
| | - Evgeny Y Tsymbal
- Department of Physics and Astronomy, University of Nebraska , Lincoln, Nebraska 68588, United States
- Nebraska Center for Materials and Nanoscience, University of Nebraska , Lincoln, Nebraska 68588, United States
| | - Vitaly Alexandrov
- Department of Chemical and Biomolecular Engineering, University of Nebraska , Lincoln, Nebraska 68588, United States
- Nebraska Center for Materials and Nanoscience, University of Nebraska , Lincoln, Nebraska 68588, United States
| | - Chang-Beom Eom
- Department of Materials Science and Engineering, University of Wisconsin-Madison , Madison, Wisconsin 53706, United States
| | - Alexei Gruverman
- Department of Physics and Astronomy, University of Nebraska , Lincoln, Nebraska 68588, United States
- Nebraska Center for Materials and Nanoscience, University of Nebraska , Lincoln, Nebraska 68588, United States
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