Giant Electrocaloric Response Over A Broad Temperature Range in Modified BaTiO3 Ceramics

Abstract

A giant electrocaloric effect (ECE) near room temperature is reported in a lead‐free bulk inorganic material. By tuning Ba(ZrxTi1–x)O3 compositions which also exhibit relaxor ferroelectric response to near the invariant critical point, the Ba(ZrxTi1–x)O3 bulk ceramics at x ∼ 0.2 exhibit a large adiabatic temperature drop of 4.5 K, a large isothermal entropy change of 8 J kg−1 K−1, and a large EC coefficient (|ΔTc/ΔE| = 0.52 × 10−6 KmV−1 and ΔS/ΔE = 0.93 × 10−6 J m kg−1 K−1 V−1) over a 30 K temperature range. These properties added together indicate a general solution of the electrocaloric materials with high performance for practical cooling applications.