Enhanced electrocaloric effect in lead-free BaTi1−xSnxO3 ceramics near room temperature

The electrocaloric effect in lead-free BaTi1−xSnxO3 (BTSn, x = 0.08, 0.105, and 0.14) ferroelectric ceramics was studied by using an indirect method. It was found that the largest electrocaloric response could be achieved in BTSn with x = xQP = 0.105 near room temperature with an adiabatic temperature change ΔT of 0.61 K and an electrocaloric strength ΔT/ΔE of 0.31 K mm kV−1, under a modest electric field ΔE of 20 kV cm−1, which is comparable with the best values reported in lead-free materials. These enhanced values are attributed to the multiphase (four phases) coexistence at x = xQP corresponding to the quasi-quadruple point composition.