Simulations of gradual domain-switching in polycrystalline ferroelectrics using an optimization-based, multidomain-grain model

An optimization-based computational model is proposed to study the constrained domain switching in polycrystalline ferroelectrics composed of numerous grains, each of which consists of multiple domains. Domain switching is realized by an optimization algorithm to minimize the free energy of each grain and is thus a gradual process with applied loading. Similar to phase field modeling, no priori domain-switching criterion is imposed in the proposed model and its computational efficiency is much higher. The domain textures evolution process can also be captured. Simulation results on both tetragonal and rhombohedral PZT ceramics illustrate the efficiency of this model.