Atomistic Model Calculation of Stress-Induced Domain Wall Instability in PbTiO₃ Using Shell Model

Abstract

While ferroelectric perovskites are promising materials for various applications, stress-induced change in microscopic structure is believed to be a major culprit of functional deterioration. In this study, we investigate stress-induced motion of the 90° domain wall (DW) in PbTiO₃ by shell model atomistic model calculation. Firstly, we examine the validity of the shell model potential for deformation problems. We find a good agreement with an ab initio study in critical shear stress for DW motion at 0 K. Secondly, we consider the effect of simulation cell size to find significant effect on shear modulus and the critical shear stress of DW motion, which may indicate that DW has a long-range interaction due to induced electric field.