Enhanced electrocaloric effect in BaTiO 3 ‐based ceramics over a wide working temperature range by domain engineering

Abstract BaTiO 3 ‐based lead‐free ferroelectric ceramics are among the most widely utilized materials in contemporary industrial applications and exhibit a high potential for large electrocaloric effect under moderate electric fields. In this study, La 3+ and Nb 5+ were introduced into BaSn 0.05 Ti 0.95 O 3 ceramics. By adding a small amount of the dopants, the tetragonality of BaSn 0.05 Ti 0.95 O 3 was weakened, causing the phase transition peak to shift to room temperature. Simultaneously, the domain structure was optimized, successfully achieving the concurrent existence of both ferroelectric domains and nanodomains. Thus, the working temperature range ( T span ) and adiabatic temperature change (∆ T ) are effectively balanced. Finally, a large ∆ T of 1.31 K under an electric field of 50 kV/cm was attained at x  = 0.0125. In addition, the Δ T /Δ E reached 0.262 × 10 −6 K m/V, and the T span (∆ T ≥ 0.8 ∆ T max ) reached 54°C indicating that this ceramic is a high‐performance electrocaloric material for solid‐state cooling applications.