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

A giant electrocaloric effect (ECE) near room temperature is reported in a lead‐free bulk inorganic material. By tuning Ba(Zr x Ti 1–x )O 3 compositions which also exhibit relaxor ferroelectric response to near the invariant critical point, the Ba(Zr x Ti 1–x )O 3 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 (|ΔT c /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.