Chiara Ricca^1*, Nicolas Niederhauser¹, 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:m9-9d [version v2]

Publication date: Dec 22, 2020

How to cite this record

Chiara Ricca, Nicolas Niederhauser, Ulrich Aschauer, Local polarization in oxygen-deficient LaMnO3 induced by charge localization in the Jahn-Teller distorted structure, Materials Cloud Archive 2020.166 (2020), doi: 10.24435/materialscloud:m9-9d.

Description

The functional properties of transition metal perovskite oxides are known to result from a complex interplay of magnetism, polarization, strain, and stoichiometry. Here, we show that for materials with a cooperative Jahn-Teller distortion, such as LaMnO3 (LMO), the orbital order can also couple to the defect chemistry and induce novel material properties. At low temperatures, LMO exhibits a strong Jahn-Teller distortion that splits the eg orbitals of the high-spin Mn3+ ions and leads to alternating long, short, and intermediate Mn-O bonds. Our DFT+U calculations show that, as a result of this orbital order, the charge localization in LMO upon oxygen vacancy formation differs from other manganites, like SrMnO3, where the two extra electrons reduce the two Mn sites adjacent to the vacancy. In LMO, relaxations around the defect depend on which type of Mn-O bond is broken, affecting the d-orbital energies and leading to asymmetric and hence polar excess electron localization with respect to the vacancy. Moreover, we show that the Mn-O bond lengths, the orbital order and consequently the charge localization and polarity are tunable via strain.

Materials Cloud sections using this data

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File name	Size	Description
README.txt MD5md5:bd1c2642959dd5261745cc82664344cf	3.8 KiB	The README file contains information on the notebooks and data stored in the archive.
paper_LMO_VO.tar.gz MD5md5:cbfadb6a9a8d6b86a6a8b42cbaa948c2	3.6 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 SNSF PRACE LaMnO3 oxygen vacancies polarization Jahn-Teller distortion