Electrocaloric Effect in Sn- and Y-Codoped BaTiO_3 Ceramics

摘要

BaSnxTi_(1–x)O_3 + 0.5 mol% Y ceramics (x = 0.06, 0.08, 0.11, and 0.13) are synthesizedusing citrate combustion technique and the electrocaloric effect (ECE) isinvestigated. Dense microstructures with fine grain are observed as increasing Sncontents. The dielectric results reveal that T_(O–T) (tetragonal-to-orthorhombicphase) shifts toward higher temperature, whereas T_C (cubic-to-tetragonal phase)shifts toward lower temperature as increasing Sn, and T_(O–T) merges with T_C atx = 0.11. An improving EC temperature change accompanying with large electrocaloricefficiency (ΔT/ΔE) of 0.28 × 10~(-6)K mV~(-1) over a wide temperaturespan is obtained at x = 0.11 under electric field of 50 kV cm~(-1). The enhanced ECEis mainly attributed to the multiphase coexistence. The dielectric properties andthe grain boundary resistance are enhanced by optimizing Sn doping contents.