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Ferroelectricity promoted by cation/anion divacancies in SrMnO(3)

We investigate the effect of polar Sr–O vacancy pairs on the electric polarization of SrMnO(3) (SMO) thin films using density functional theory (DFT) calculations. This is motivated by indications that ferroelectricity in complex oxides can be engineered by epitaxial strain but also via the defect c...

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Detalles Bibliográficos
Autores principales: Ricca, Chiara, Berkowitz, Danielle, Aschauer, Ulrich
Formato: Online Artículo Texto
Lenguaje:English
Publicado: The Royal Society of Chemistry 2021
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8495715/
https://www.ncbi.nlm.nih.gov/pubmed/34707873
http://dx.doi.org/10.1039/d1tc02317a
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author Ricca, Chiara
Berkowitz, Danielle
Aschauer, Ulrich
author_facet Ricca, Chiara
Berkowitz, Danielle
Aschauer, Ulrich
author_sort Ricca, Chiara
collection PubMed
description We investigate the effect of polar Sr–O vacancy pairs on the electric polarization of SrMnO(3) (SMO) thin films using density functional theory (DFT) calculations. This is motivated by indications that ferroelectricity in complex oxides can be engineered by epitaxial strain but also via the defect chemistry. Our results suggest that intrinsic doping by cation and anion divacancies can induce a local polarization in unstrained non-polar SMO thin films and that a ferroelectric state can be stabilized below the critical strain of the stoichiometric material. This polarity is promoted by the electric dipole associated with the defect pair and its coupling to the atomic relaxations upon defect formation that polarize a region around the defect. This suggests that polar defect pairs affect the strain-dependent ferroelectricity in semiconducting antiferromagnetic SMO. For metallic ferromagnetic SMO we find a much weaker coupling between the defect dipole and the polarization due to much stronger electronic screening. Coupling of defect-pair dipoles at high enough concentrations along with their switchable orientation thus makes them a promising route to affect the ferroelectric transition in complex transition metal oxide thin films.
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spelling pubmed-84957152021-10-25 Ferroelectricity promoted by cation/anion divacancies in SrMnO(3) Ricca, Chiara Berkowitz, Danielle Aschauer, Ulrich J Mater Chem C Mater Chemistry We investigate the effect of polar Sr–O vacancy pairs on the electric polarization of SrMnO(3) (SMO) thin films using density functional theory (DFT) calculations. This is motivated by indications that ferroelectricity in complex oxides can be engineered by epitaxial strain but also via the defect chemistry. Our results suggest that intrinsic doping by cation and anion divacancies can induce a local polarization in unstrained non-polar SMO thin films and that a ferroelectric state can be stabilized below the critical strain of the stoichiometric material. This polarity is promoted by the electric dipole associated with the defect pair and its coupling to the atomic relaxations upon defect formation that polarize a region around the defect. This suggests that polar defect pairs affect the strain-dependent ferroelectricity in semiconducting antiferromagnetic SMO. For metallic ferromagnetic SMO we find a much weaker coupling between the defect dipole and the polarization due to much stronger electronic screening. Coupling of defect-pair dipoles at high enough concentrations along with their switchable orientation thus makes them a promising route to affect the ferroelectric transition in complex transition metal oxide thin films. The Royal Society of Chemistry 2021-09-02 /pmc/articles/PMC8495715/ /pubmed/34707873 http://dx.doi.org/10.1039/d1tc02317a Text en This journal is © The Royal Society of Chemistry https://creativecommons.org/licenses/by/3.0/
spellingShingle Chemistry
Ricca, Chiara
Berkowitz, Danielle
Aschauer, Ulrich
Ferroelectricity promoted by cation/anion divacancies in SrMnO(3)
title Ferroelectricity promoted by cation/anion divacancies in SrMnO(3)
title_full Ferroelectricity promoted by cation/anion divacancies in SrMnO(3)
title_fullStr Ferroelectricity promoted by cation/anion divacancies in SrMnO(3)
title_full_unstemmed Ferroelectricity promoted by cation/anion divacancies in SrMnO(3)
title_short Ferroelectricity promoted by cation/anion divacancies in SrMnO(3)
title_sort ferroelectricity promoted by cation/anion divacancies in srmno(3)
topic Chemistry
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8495715/
https://www.ncbi.nlm.nih.gov/pubmed/34707873
http://dx.doi.org/10.1039/d1tc02317a
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AT aschauerulrich ferroelectricitypromotedbycationaniondivacanciesinsrmno3