A computational search for wurtzite-structured ferroelectrics with low coercive voltages
Ferroelectricity has recently been observed in wurtzite-structured Sc-doped AlN thin films, five years after our initial prediction of ferroelectricity in wurtzite compounds based on first-principles calculations. The thin films exhibited a much higher coercive voltage (3 MV/cm) than that of convent...
Main Authors: | , , , , , , , , , , |
---|---|
Format: | Article |
Language: | English |
Published: |
AIP Publishing LLC
2020-12-01
|
Series: | APL Materials |
Online Access: | http://dx.doi.org/10.1063/5.0023626 |
id |
doaj-d1980d4c158143828500e4a91f6c727f |
---|---|
record_format |
Article |
spelling |
doaj-d1980d4c158143828500e4a91f6c727f2021-01-05T15:00:42ZengAIP Publishing LLCAPL Materials2166-532X2020-12-01812121102121102-910.1063/5.0023626A computational search for wurtzite-structured ferroelectrics with low coercive voltagesHiroki Moriwake0Rie Yokoi1Ayako Taguchi2Takafumi Ogawa3Craig A. J. Fisher4Akihide Kuwabara5Yukio Sato6Takao Shimizu7Yosuke Hamasaki8Hiroshi Takashima9Mitsuru Itoh10Nanostructures Research Laboratory, Japan Fine Ceramics Center, Nagoya 456-8587, JapanNanostructures Research Laboratory, Japan Fine Ceramics Center, Nagoya 456-8587, JapanNanostructures Research Laboratory, Japan Fine Ceramics Center, Nagoya 456-8587, JapanNanostructures Research Laboratory, Japan Fine Ceramics Center, Nagoya 456-8587, JapanNanostructures Research Laboratory, Japan Fine Ceramics Center, Nagoya 456-8587, JapanNanostructures Research Laboratory, Japan Fine Ceramics Center, Nagoya 456-8587, JapanDepartment of Materials Science and Engineering, Kyushu University, Fukuoka 819-0395, JapanResearch Center for Functional Materials, National Institute for Materials Science, Tsukuba 305-0047, JapanDepartment of Applied Physics, National Defense Academy, Yokosuka 239-8686, JapanResearch Institute for Advanced Electronics and Photonics, National Institute of Advanced Industrial Science and Technology, Tsukuba 305-8568, JapanResearch Institute for Advanced Electronics and Photonics, National Institute of Advanced Industrial Science and Technology, Tsukuba 305-8568, JapanFerroelectricity has recently been observed in wurtzite-structured Sc-doped AlN thin films, five years after our initial prediction of ferroelectricity in wurtzite compounds based on first-principles calculations. The thin films exhibited a much higher coercive voltage (3 MV/cm) than that of conventional perovskite-structured ferroelectric material PbTiO3, however, making it difficult to switch the films’ polarity and limiting their practical application. To identify tetrahedral ferroelectric materials with low coercive voltages, we have carried out a wider exploration of candidate binary compounds, from halides to chalcogenides to pnictogenides, using first-principles methods. The overall trend is for polarization switching barriers to decrease with decreasing anion-to-cation radius ratio, with the lowest barriers found in monovalent compounds such as the copper and silver halides; e.g., CuCl is calculated to have a switching barrier of 0.17 eV/f.u. and that of AgI is 0.22 eV/f.u., values similar in magnitude to that of PbTiO3 (0.20 eV/f.u.). Applying an epitaxial tensile strain to the basal plane is also effective for lowering the potential barrier further, with barriers in both AgI and CuCl decreasing to 0.04 eV/f.u. when a 5% in-plane expansion is applied. The results suggest that tetrahedral ferroelectrics with moderate coercive voltages (below 100 kV/cm) should be achievable.http://dx.doi.org/10.1063/5.0023626 |
collection |
DOAJ |
language |
English |
format |
Article |
sources |
DOAJ |
author |
Hiroki Moriwake Rie Yokoi Ayako Taguchi Takafumi Ogawa Craig A. J. Fisher Akihide Kuwabara Yukio Sato Takao Shimizu Yosuke Hamasaki Hiroshi Takashima Mitsuru Itoh |
spellingShingle |
Hiroki Moriwake Rie Yokoi Ayako Taguchi Takafumi Ogawa Craig A. J. Fisher Akihide Kuwabara Yukio Sato Takao Shimizu Yosuke Hamasaki Hiroshi Takashima Mitsuru Itoh A computational search for wurtzite-structured ferroelectrics with low coercive voltages APL Materials |
author_facet |
Hiroki Moriwake Rie Yokoi Ayako Taguchi Takafumi Ogawa Craig A. J. Fisher Akihide Kuwabara Yukio Sato Takao Shimizu Yosuke Hamasaki Hiroshi Takashima Mitsuru Itoh |
author_sort |
Hiroki Moriwake |
title |
A computational search for wurtzite-structured ferroelectrics with low coercive voltages |
title_short |
A computational search for wurtzite-structured ferroelectrics with low coercive voltages |
title_full |
A computational search for wurtzite-structured ferroelectrics with low coercive voltages |
title_fullStr |
A computational search for wurtzite-structured ferroelectrics with low coercive voltages |
title_full_unstemmed |
A computational search for wurtzite-structured ferroelectrics with low coercive voltages |
title_sort |
computational search for wurtzite-structured ferroelectrics with low coercive voltages |
publisher |
AIP Publishing LLC |
series |
APL Materials |
issn |
2166-532X |
publishDate |
2020-12-01 |
description |
Ferroelectricity has recently been observed in wurtzite-structured Sc-doped AlN thin films, five years after our initial prediction of ferroelectricity in wurtzite compounds based on first-principles calculations. The thin films exhibited a much higher coercive voltage (3 MV/cm) than that of conventional perovskite-structured ferroelectric material PbTiO3, however, making it difficult to switch the films’ polarity and limiting their practical application. To identify tetrahedral ferroelectric materials with low coercive voltages, we have carried out a wider exploration of candidate binary compounds, from halides to chalcogenides to pnictogenides, using first-principles methods. The overall trend is for polarization switching barriers to decrease with decreasing anion-to-cation radius ratio, with the lowest barriers found in monovalent compounds such as the copper and silver halides; e.g., CuCl is calculated to have a switching barrier of 0.17 eV/f.u. and that of AgI is 0.22 eV/f.u., values similar in magnitude to that of PbTiO3 (0.20 eV/f.u.). Applying an epitaxial tensile strain to the basal plane is also effective for lowering the potential barrier further, with barriers in both AgI and CuCl decreasing to 0.04 eV/f.u. when a 5% in-plane expansion is applied. The results suggest that tetrahedral ferroelectrics with moderate coercive voltages (below 100 kV/cm) should be achievable. |
url |
http://dx.doi.org/10.1063/5.0023626 |
work_keys_str_mv |
AT hirokimoriwake acomputationalsearchforwurtzitestructuredferroelectricswithlowcoercivevoltages AT rieyokoi acomputationalsearchforwurtzitestructuredferroelectricswithlowcoercivevoltages AT ayakotaguchi acomputationalsearchforwurtzitestructuredferroelectricswithlowcoercivevoltages AT takafumiogawa acomputationalsearchforwurtzitestructuredferroelectricswithlowcoercivevoltages AT craigajfisher acomputationalsearchforwurtzitestructuredferroelectricswithlowcoercivevoltages AT akihidekuwabara acomputationalsearchforwurtzitestructuredferroelectricswithlowcoercivevoltages AT yukiosato acomputationalsearchforwurtzitestructuredferroelectricswithlowcoercivevoltages AT takaoshimizu acomputationalsearchforwurtzitestructuredferroelectricswithlowcoercivevoltages AT yosukehamasaki acomputationalsearchforwurtzitestructuredferroelectricswithlowcoercivevoltages AT hiroshitakashima acomputationalsearchforwurtzitestructuredferroelectricswithlowcoercivevoltages AT mitsuruitoh acomputationalsearchforwurtzitestructuredferroelectricswithlowcoercivevoltages AT hirokimoriwake computationalsearchforwurtzitestructuredferroelectricswithlowcoercivevoltages AT rieyokoi computationalsearchforwurtzitestructuredferroelectricswithlowcoercivevoltages AT ayakotaguchi computationalsearchforwurtzitestructuredferroelectricswithlowcoercivevoltages AT takafumiogawa computationalsearchforwurtzitestructuredferroelectricswithlowcoercivevoltages AT craigajfisher computationalsearchforwurtzitestructuredferroelectricswithlowcoercivevoltages AT akihidekuwabara computationalsearchforwurtzitestructuredferroelectricswithlowcoercivevoltages AT yukiosato computationalsearchforwurtzitestructuredferroelectricswithlowcoercivevoltages AT takaoshimizu computationalsearchforwurtzitestructuredferroelectricswithlowcoercivevoltages AT yosukehamasaki computationalsearchforwurtzitestructuredferroelectricswithlowcoercivevoltages AT hiroshitakashima computationalsearchforwurtzitestructuredferroelectricswithlowcoercivevoltages AT mitsuruitoh computationalsearchforwurtzitestructuredferroelectricswithlowcoercivevoltages |
_version_ |
1724348142256652288 |