Structural stability and formability of ABO₃-type perovskite compounds

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⁺B⁵⁺O₃-type > A²⁺B⁴⁺O₃-type > A³⁺B³⁺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.