Domain switching in ferroelectric ceramics beyond Taylor bound

摘要

Domain switching in ferroelectric ceramics is a collective process among all the grains, and it was postulated that Taylor bound, which requires the transformation strain and spontaneous polarization in all the grains to remain uniform during switching, gives a good estimate on the extent of domain switching in ferroelectric ceramics. In this paper, we develop a two-scale micromechanics scheme to analyze domain switching in ferroelectric ceramics during poling. The disturbance field and the resulted energy variation are determined first using an inclusion method, and domain switching is then analyzed using energy minimization approach. It is demonstrated that a complete poling that exhausts both 90° and 180° domain switching is highly unlikely, so is a complete 180° domain switching that exhausts 180° domain switching but does not allow any 90° domain switching. It is also observed that any 90° domain switching beyond Taylor bound is rather difficult, while limited 180° domain switching beyond Taylor bound is possible. The analysis offers new insight into the domain switching process in ferroelectric ceramics and their nonlinear electromechanical behaviors.