An atlas of room-temperature stability and vibrational anharmonicity of cubic perovskites

Abstract

perovskites, encompassing the chemical space of halides, oxides and chalcogenides. We show that halides are systematically more stable and less anharmonic than oxides/chalcogenides. New metrics are developed to quantify the significance of higher order force constants to the strong anharmonicities in room-temperature stable perovskites through both perturbative and temperature-dependent effective potential approaches. The new database and theoretical methods established in this work pave a pathway to deepen the fundamental understanding of lattice dynamics and facilitate the developments of mutifunctional materials with designed physical and chemical properties, such as thermal insulators and high-entropy perovskites.

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