Influence of sintering temperature on grain size and electrocaloric effect of barium titanate ceramics

A theoretical study of the polarization distribution and mechanical stresses in a ferroelectric ball located an unlimited dielectric space has been carried out. The is covered with air shell. external electric field far from assumed to be uniform. satisfies nonlinear Landau--Ginzburg equation, which takes into account presence electrostriction. It also that for small ball, effect local elastic on can replaced by their homogenized value over volume ball. Under this assumption, stress obtained both outside it. dependence Curie--Weiss temperature radius derived. resulting solution used simulate properties microgranular ceramics. Along developed model, series experiments was out measure constant electrocaloric (ECE) BaTiO 3 ceramics synthesized at different temperatures. change during ECE measured direct methods. greatest achieved 1350 o C. magnitude 2 mV/m Delta T=0.42 K. observed experimental results demonstrate possibility using four-phase model predict sintering temperature. Keywords: ferroelectrics, effect, barium titanate (BaTiO ), granular media, temperature, grain size.