Structure and Stability of TaON Polymorphs

Abstract

Abstract The stabilities and electronic structures of several polymorphs of tantalum oxynitride, TaON, were studied quantum‐chemically at density‐functional level. Results obtained by complementary quantum‐chemical techniques with wave‐functions either expanded in atom‐centered functions or in plane waves were compared. Close agreement was obtained for the relative stabilities of the baddeleyite, anatase, rutile, and fluorite phases of TaON. The effect of anion distribution on the structural parameters and the lattice energies of the anatase and rutile polymorphs was investigated. The calculated band structure of the polymorphs is compared with available experimental information.