Electric field induced phase transitions and electrocaloric effect of La3+ doped Pb(Zr,Sn,Ti)O3 ceramics

Electrocaloric effect (ECE) is considered well applicable in the field of next generation solid state refrigeration technology. In this article, the structural properties and ECE response were altered and optimized by tailoring the Zr/Ti molar ratio in (Pb0.94La0.04)(ZrxSn0.30Ti0.70-x)O3 (x = 0.54, 0.52, 0.50 and 0.48) polycrystalline ceramics. Multiple phase transition behaviors including antiferroelectric (AFE) state to ferroelectric (FE) state transition under applied electric field, depolarization phase change behavior and AFE state to paraelectric state (PE) transition were observed, and their effects on the ECE response were investigated in detail. Significant improvement of ECE adiabatic temperature change of 1.04 K at room temperature (30 ?C) was obtained by Maxwell method in (Pb0.94La0.04)(Zr0.52Sn0.30Ti0.18)O3 bulk ceramic through AFE?FE phase transition, while the highest ?T of 2.73 K with electrocaloric strength (?T??E- 1) of 0.039 K cm kV-1 were observed in (Pb0.94La0.04) (Zr0.50Sn0.30Ti0.20)O3 bulk ceramic at temperature close to its Curie peak. The high ECE temperature change and ECE strength make them to be candidates for using in next generation solid-state refrigeration device.