Phase-field modeling of ferroelectric switching

A phase-field model with general kinetics

Existing phase-field models for polarization switching in ferroelectrics are based on the Allen-Cahn equation, which provides a linear kinetic relation between the thermodynamic driving force exerted on a domain wall and its normal velocity. By contrast, experimental observations rather suggest a non-linear relation between velocity and driving.  

We develop an alternative phase-field model for polarization evolution, which by incorporating both non-linear domain wall kinetics and an independent criterion for nucleation, permits a physically-informed description of domain evolution. This new formulation pave the ways to a faithful account of the sequence of domain nucleation and growth underlying the macroscopic response of ferroelectrics. In this respect, it provides a suitable model for understanding rate-dependent effects on polarization switching.