A constrained domain-switching model for polycrystalline ferroelectric ceramics. Part I: Model formulation and application to tetragonal materials

Abstract A micromechanical model is proposed to study the constrained domain-switching process in polycrystalline ferroelectric ceramics. It is assumed that the depolarization field induced by domain switching is completely compensated by free charges, while the stress caused by non-180° switching is considered in an Eshelby inclusion manner. The model assumes that each grain contains multi-domains and the domain-switching criterion is based on potential energy density. Two switching options, which are based on Hwang et al. [Hwang SC, Lynch CS, McMeeking RM. Acta Metall Mater 1995;43:2073] and Berlincourt and Krueger [Berlincourt D, Krueger HHA. J Appl Phys 1959;30:1804], are used in the model development. Details of the switching process are analyzed for tetragonal ferroelectric/ferroelastic ceramics under electric loading or uniaxial compression (tension) by using an inverse-pole-figure method. Numerical results show that during electric poling, only a few per cent 90° switching can occur in BaTiO3 ceramics, which agrees well with experimental observations.