Solving the puzzle of the dielectric nature of tantalum oxynitride perovskites

Abstract

Abstract The dielectric properties of tantalum oxynitride perovskites are of interest because of the unique optical characteristics of these compounds based on their visible light absorption. Unfortunately, such perovskites are thermally metastable, which makes it challenging to prepare high-quality bulk samples for the study of dielectric properties. Recently, studies of small single crystals of BaTaO2N showed the compound to be ferroelectric, and this can be well explained based on the non-centrosymmetric crystal structure proposed previously using first-principles and molecular dynamic investigations.