Structural stability and formability of ABO3-type perovskite compounds

Abstract

On the basis of the bond-valence model (BVM) and structure-map technology, the structural stability and formability of ABO(3)-type perovskite compounds were investigated in 376 ABO(3)-type compounds. A new criterion of structural stability for ABO(3)-type perovskite compounds has been established by the bond-valence calculated tolerance factors, which are in the range 0.822-1.139. All global instability indices for ABO(3)-type perovskite compounds are found to be less than 1.2 v.u. (valence units) and increase with a decrease in oxidation state of the B cations (i.e. structural stability in the formation of an ideal cubic perovskite follows the order A(+)B(5+)O(3)-type > A(2+)B(4+)O(3)-type > A(3+)B(3+)O(3)-type). Three new two-dimensional structure maps were constructed based on the ideal A-O and B-O bond distances derived from the BVM. These maps indicate the likelihood of particular perovskite compounds being formed. The present work enables novel perovskite and perovskite-related compounds to be explored by screening all the possible elemental combinations in future crystal engineering.