Phase stability and structural transitions in compositionally complex LnMO3 perovskites
Artikel i vetenskaplig tidskrift, 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

Författare

J. Cedervall

STFC Rutherford Appleton Laboratory

Stockholms universitet

Rebecca Clulow

Uppsala universitet

Hanna L.B. Boström

Uppsala universitet

Max-Planck-Gesellschaft

Deep C. Joshi

Uppsala universitet

Mikael Andersson

Chalmers, Kemi och kemiteknik, Energi och material, Oorganisk miljökemi 2

Uppsala universitet

R. Mathieu

Uppsala universitet

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 universitet

Pedro Berastegui

Uppsala universitet

Samrand Shafeie

Uppsala universitet

Chalmers, Fysik, Material- och ytteori

Journal of Solid State Chemistry

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

Vol. 300 122213

Ämneskategorier

Oorganisk kemi

Materialkemi

Den kondenserade materiens fysik

DOI

10.1016/j.jssc.2021.122213

Mer information

Senast uppdaterat

2021-06-22