Chiara Ricca^1*, Danielle Berkowitz¹, Ulrich Aschauer^1*

1 Department of Chemistry and Biochemistry and National Centre for Computational Design and Discovery of Novel Materials (MARVEL), University of Bern, Freiestrasse 3, CH-3012 Bern, Switzerland

* Corresponding authors emails: chiara.ricca@dcb.unibe.ch, ulrich.aschauer@dcb.unibe.ch

DOI10.24435/materialscloud:g7-e7 [version v1]

Publication date: Jun 24, 2021

How to cite this record

Chiara Ricca, Danielle Berkowitz, Ulrich Aschauer, Ferroelectricity promoted by cation/anion divacancies in SrMnO3, Materials Cloud Archive 2021.93 (2021), doi: 10.24435/materialscloud:g7-e7.

Description

We investigate the effect of polar Sr-O vacancy pairs on the electric polarization of SrMnO3 (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.

Materials Cloud sections using this data

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File name	Size	Description
README.txt MD5md5:26e1c6d77b59e4c471581d56627a7ffe	3.2 KiB	The README file contains information on the notebooks and data stored in the archive.
paper_VSrVO_SMO.tar.gz MD5md5:6eda1f2e5c52ce26753753aa8ca5edc1	2.8 GiB	The compressed file contains the python and bash scripts, and the folders with the data used in the Jupiter notebook to produce the plots and tables found in the publication.

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External references

Keywords

MARVEL/DD5 CSCS SNSF DFT+U SrMnO3 polarization point defects cation/anion divacancies ferroelectricity strain thin films