Composition dependence of giant electrocaloric effect in PbxSr1-xTiO3 ceramics for energy-related applications

PbxSr1-xTiO3 (x = 0.30, 0.35, 0.40, 0.45, 0.50 and 0.55) ceramics were fabricated by a solid-state reaction route. X–ray diffraction data at room temperature show PST samples shift from cubic to tetragonal phase with the increase of Pb2+ content. The microstructures were observed by scanning electron microscopy. Dielectric measurement was employed to investigate the ferroelectric–paraelectric phase transition behavior. Temperature dependent polarization–electric field hysteresis loops were conducted to study the electrocaloric effect (ECE) of the ferroelectric ceramics by indirect methods over a wide temperature range. Direct measurement of temperature change (ΔT) at room temperature for all samples can achieve 0.79–1.86 K. What's more, a giant ECE (ΔT = 2.05 K, EC strength (ΔT/ΔE) = 0.51 × 10−6 K m/V, under 40 kV/cm) was obtained in the sample of x = 0.35 near phase transition temperature. Our results suggest that the ceramics are promising cooling materials with excellent EC properties for energy related applications. Keywords: PbxSr1-xTiO3 ceramics, Electrocaloric effect, Phase transition, Energy applications