Questions on ferroelectrics: why tetragonal ferroelectric ceramics are difficult to pole while rhombohedral ceramics easy to?
It may be well known to researchers on ferroelectrics that tetragonal ferroelectric ceramics, such as BaTiO3, Ti-rich lead titanate zirconate (PZT), are difficult to pole even using a high DC field with long holding time. While the rhombohedral PZT or PZT near the morphotropic phase boundary (MPB) are easy to pole, especially the latter. Why?