Chiara Ricca^1,2*, Ulrich Aschauer^1,2

1 Department of Chemistry and Biochemistry, University of Bern, Freiestrasse 3, CH-3012 Bern, Switzerland

2 National Centre for Computational Design and Discovery of Novel Materials (MARVEL), Switzerland

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

DOI10.24435/materialscloud:d0-fb [version v1]

Publication date: Jul 01, 2021

How to cite this record

Chiara Ricca, Ulrich Aschauer, Interplay between polarization, strain and defect-pairs in Fe-doped SrMnO3-δ, Materials Cloud Archive 2021.101 (2021), https://doi.org/10.24435/materialscloud:d0-fb

Description

Defect chemistry, strain, and structural, magnetic and electronic degrees of freedom constitute a rich space for the design of functional properties in transition metal oxides. Here, we show that it is possible to engineer polarity and ferroelectricity in non-polar perovskite oxides via polar defect pairs formed by anion vacancies coupled to substitutional cations. We use a self-consistent site-dependent DFT+U approach that accounts for local structural and chemical changes upon defect creation and which is crucial to reconcile predictions with the available experimental data. Our results for Fe-doped oxygen-deficient SrMnO3 show that substitutional Fe and oxygen vacancies can promote polarity due to an o -center displacement of the defect charge resulting in a net electric dipole moment, which polarizes the lattice in the defect neighborhood. The formation of these defects and the resulting polarization can be tuned by epitaxial strain, resulting in enhanced polarization also for strain values lower than the ones necessary to induce a polar phase transition in undoped SrMnO3. For high enough defect concentrations, these defect dipoles couple in a parallel fashion, thus enabling defect- and strain-based engineering of ferroelectricity in SrMnO3.

Materials Cloud sections using this data

Files

File name	Size	Description
paper_SMO_Fe_VO.tar.gz MD5md5:b260a96c1dc63df5a11c84ff04c91882	4.4 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.
README.txt MD5md5:e50aa25c49c466bd87f880197725beba	4.0 KiB	The README file contains information on the notebooks and data stored in the archive.

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External references

Keywords

SNSF CSCS MARVEL/DD5 Defect pair polarization ferroelectricity SrMnO3 strain thin film doping point defect self-consistent DFT+U