Variations in the microstructure and properties of multicomponent ferroelectric ceramics as a result of its modification by barium

The specific features of the microstructure of multicomponent solid solutions, based on relaxor ferroelectrics both unmodified and modified by barium, were observed. A reduction of tetragonal distortion in the unit cell in ceramics containing Ba, as well as an increase in the size of its crystallites (which is a consequence of this reduction), facilitates domain reorientation owing to an increase in their mobility. This is the main reason for the sharp increase in the relative permittivity εT33/ε0 of the poled samples of modified ceramics, and the variations of some parameters that characterize the piezoelectric response.