Rattling Phonon Modes in Quadruple Perovskites

Abstract

Rattling phonon modes are known to be the origin of various anomalous physical properties such as superconductivity, suppression of thermal conductivity, enhancement of specific heat etc. By means of DFT + U calculations we directly show the presence of the rattling mode in the quadruple perovskites CuCu3V4O12 and CuCu3Fe2Re2O12 and argue that this might appear in others as well. It is demonstrated that Cu ions at UAU sites vibrate in the center of the icosahedral oxygen O12 cages and the corresponding potential has a complicated form with many local minima. © 2023, Pleiades Publishing, Ltd.