Growth kinetics of core-shell-structured grains and dielectric constant in rare-earth-doped BaTiO ₃ ceramics

The solute-drag-dependent growth kinetics of core-shell-structured grains in rare-earth-doped BaTi O3 ceramics was studied based on an analytical description of the diffusion of rare-earth atoms doped. Dependence of the sizes of grain core and shell on the sintering conditions, dopant content, and starting powder size was quantitatively revealed. The effective dielectric constant of the ceramics was calculated in terms of the relative contents of the ferroelectric core and paraelectric shell. The calculations are in good agreement with the experimental observations.