Electrocaloric Effect in Pb0.3CaxSr0.7-xTiO3 Ceramics Near Room Temperature

Abstract

The electrocaloric (EC) effect is strongly related to interaction of polarization and temperature changes, showing great potential in high-efficient solid state refrigeration. This work focuses on the Pb0.3CaxSr0.7-xTiO3 (PCST(x), x = 0.00, 0.05, 0.10, 0.15) ceramics in which the influence of Ca content on dielectric and ferroelectric property under electric field was studied, and the EC temperature change was calculated through indirect method. Substitution of Ca largely modifies the diffused phase transition behaviors of PCST ceramics, which the diffusion exponent of PCST(0.05) increases with electric field up, indicating a promising wide temperature range of large electrocaloric effect. Thus, the largest adiabatic temperature change (1.71 K) is obtained near the room temperature in PCST(0.05) by indirect method. With an electric field of 8 kV/mm, PCST(0.05) ceramic shows good EC effect in a wide temperature range that the adiabatic temperature change is larger than 1 K from 5 ℃ to 70 ℃.