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 ABO3-type perovskite compounds were investigated in 376 ABO3-type compounds. A new criterion of structural stability for ABO3-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 ABO3-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+O3-type > A 2+ B 4+O3-type > A 3+ B 3+O3-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.