The electrocaloric effect in intrinsic-acceptor-doped Ba(Ti,Ce)O₃-(Ba,Ca) TiO₃ ceramics

The electrocaloric effect (ECE) of intrinsic-acceptor-doped ferroelectric system (1-x)Ba(Ti0.9Ce0.1)O-3-x (Ba0.7Ca0.3)TiO3 (x = 03,0.5) has been studied by indirect and direct approaches. It was found that the indirect approach based on Maxwell equation is not appropriate for measuring the ECE of this acceptor-doped system. More importantly, a relatively large electrocaloric response is obtained at temperatures far below T-c (maximum difference similar to 75 degrees C), which can reach 75%similar to 90% of the maximum electrocaloric effect near T-c. The unique characteristics of this acceptor-doped system have been explained by the existence of orientable defect dipoles. Our work could stimulate the design of temperature-stable electrocaloric effect through acceptor-doping. (C) 2019 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.