Ab initio study of ABiO(3) (A = Ba, Sr, Ca) under high pressure

Author(s)
Andriy Smolyanyuk, Cesare Franchini, Lilia Boeri
Abstract

Using ab initio crystal structure prediction we study the high-pressure phase diagram of ABiO(3) bismuthates (A = Ba, Sr, Ca) in a pressure range up to 100 GPa. All compounds show a transition from the low-pressure perovskite structure to highly distorted, low-symmetry phases at high pressures (PD transition), and remain charge-disproportionated and insulating up to the highest pressure studied. The PD transition at high pressures in bismuthates can be understood as a combined effect of steric arguments and of the strong tendency of bismuth to charge-disproportionation. In fact, distorted structures permit to achieve a very efficient atomic packing, and at the same time, to have Bi-O bonds of different lengths. The shift of the PD transition to higher pressures with increasing cation size within the ABiO(3) series can be explained in terms of chemical pressure.

Organisation(s)
Computational Materials Physics
External organisation(s)
Technische Universität Graz, Università degli Studi di Roma La Sapienza, CNR, Consiglio Nazionale delle Ricerche (CNR), Istituto dei Sistemi Complessi (ISC), Ist Sistemi Complessi
Journal
Physical Review B
Volume
98
No. of pages
8
ISSN
2469-9950
DOI
https://doi.org/10.1103/PhysRevB.98.115158
Publication date
09-2018
Peer reviewed
Yes
Austrian Fields of Science 2012
Condensed matter
Keywords
Portal url
https://ucris.univie.ac.at/portal/en/publications/ab-initio-study-of-abio3-a--ba-sr-ca-under-high-pressure(8140d386-d468-4b83-ae2f-6ae3744e51e5).html