Giant Negative Electrocaloric Effect in (Pb,La)(Zr,Sn,Ti)O 3 Antiferroelectrics Near Room Temperature.

(Pb0.97 La0.02 )(Zr x Sn0.94- x Ti0.06 )O3 (PLZST) antiferroelectric ceramics with x = 0.75-0.90 have been fabricated and found to be a novel electrocaloric material system with a giant negative electrocaloric effect (Δ T = -11.5 K) and a large electrocaloric strength (|Δ T/Δ E| = 0.105 K cm kV-1 ) near room temperature. Additionally, the PLZST antiferroelectric ceramic also exhibits a large positive electrocaloric effect around the Curie temperature. The giant negative effect and the coexistence of both positive and negative electrocaloric effects in one material indicate a promising possibility to develop mid- to large-scale solid-state cooling devices with high efficiency.