Phase stability and structural transitions in compositionally complex LnMO3 perovskites
Journal article, 2021

Entropy stabilised materials have possibilities for tailoring functionalities to overcome challenges in materials science. The concept of configurational entropy can also be applied to metal oxides, but it is unclear whether these could be considered as solid solutions in the case of perovskite-structured oxides and if the configurational entropy plays a stabilising role. In this study, compositionally complex perovskite oxides, LnMO3 (Ln ​= ​La, Nd, Sm, Ca and Sr, M ​= ​Ti, Cr, Mn, Fe, Co, Ni, and Cu), are investigated for their phase stability and magnetic behaviour. Phase-pure samples were synthesised, and the room temperature structures were found to crystallise in either Pnma or R3¯c space groups, depending on the composition and the resulting tolerance factor, while the structural transition temperatures correlate with the pseudo cubic unit cell volume. The techniques used included diffraction with X-rays and neutrons, both ex- and in-situ, X-ray photoelectron spectroscopy, magnetometry as well as electron microscopy. Neutron diffraction studies on one sample reveal that no oxygen vacancies are found in the structure and that the magnetic properties are ferrimagnetic-like with magnetic moments mainly coupled antiferromagnetically along the crystallographic c-direction. X-ray photoelectron spectroscopy gave indications of the oxidation states of the constituting ions where several mixed oxidation states are observed in these valence-compensated perovskites.

Magnetism

High entropy oxides

Phase transitions

Perovskites

Author

J. Cedervall

STFC Rutherford Appleton Laboratory

Stockholm University

Rebecca Clulow

Uppsala University

Hanna L.B. Boström

Uppsala University

Max Planck Society

Deep C. Joshi

Uppsala University

Mikael Andersson

Chalmers, Chemistry and Chemical Engineering, Energy and Material

Uppsala University

R. Mathieu

Uppsala University

Premysl Beran

Nuclear Physics Institute

European Spallation Source (ESS)

Ronald I. Smith

STFC Rutherford Appleton Laboratory

Jo Chi Tseng

Deutsches Elektronen-Synchrotron (DESY)

M. Sahlberg

Uppsala University

Pedro Berastegui

Uppsala University

Samrand Shafeie

Uppsala University

Chalmers, Physics, Materials and Surface Theory

Journal of Solid State Chemistry

0022-4596 (ISSN) 1095-726X (eISSN)

Vol. 300 122213

Subject Categories

Inorganic Chemistry

Materials Chemistry

Condensed Matter Physics

DOI

10.1016/j.jssc.2021.122213

More information

Latest update

6/22/2021