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 Ba1-xLaxTiO3 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 Delta T/Delta E = 0.30 K.mm/kV near room temperature (T-C = 303 K) was obtained in Ba0.96La0.04TiO3 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.