Dynamics of antipolar distortions

Abstract

Antipolar distortions: ferroelectric-related phases evolve dynamically with temperature Temperature dependent structural dynamics in pressurized BiFeO3 are simulated and analyzed for ferroelectric-related phases. Kinnary Patel and coworkers from the University of Arkansas in US and Southern Federal University in Russia performed atomistic simulations on the dynamics of antipolar distortions, which are cation distortions against ferroelectric polarization, with respect to temperature in BiFeO3 under hydrostatic pressure. The material undergoes a paraelectric phase, an intermediate phase with long-range-ordered FeO6 octahedral tilting and a motion-mixed phase with both antipolar distortion and FeO6 octahedral tilting upon cooling. In paraelectric phase, the antipolar distortions always have high frequencies independent of temperature while they become soft with low frequencies in the intermediate and the motion-mixed phases. These results can be applied to predict dynamics of antipolar motions on the phase evolutions for other materials with similar crystal structures.