Manipulation of Curie temperature and ferroelectric polarization for large electrocaloric strength in BaTiO₃-based ceramics

Manipulation of Curie temperature and ferroelectric polarization for enhanced room temperature electrocaloric effect (ECE) was systematically investigated in lead-free Ba_1-xLa_xTiO₃ ferroelectric ceramics prepared by a two-step solid-state sintering technology. The experimental results and analysis showed that La dopants significantly influenced the morphology, Curie temperature, ferroelectric properties and electrocaloric effect of BaTiO₃ ceramics. Especially, based on the analysis and calculation via the Maxwell relationship, a large electrocaloric strength ΔT/ΔE = 0.30 K·mm/kV near room temperature (T_C = 303 K) was obtained in Ba_0.96La_0.04TiO₃ ceramic. The present work implied an effective and reliable way to realize the room temperature electrocaloric effect in lead-free ferroelectric materials for the future application of solid-state refrigeration technology.