Caloric Effects in Bulk Lead-Free Ferroelectric Ceramics for Solid-State Refrigeration

The caloric behavior of bulk (Ba0.865Ca0.135Zr0.1078Ti0.8722Fe0.01Nb0.01)O-3 (BCZTO-FeNb) with respect to multiple physical inputs is investigated. Predictions were made by using modified Maxwell's relations in conjunction with independent experimental data. BCZTO-FeNb possesses significant potential for multiple caloric effects. A peak electrocaloric effect of 0.5K (307K) was predicted for electric fields of 0-3kVmm(-1), significantly higher than for other BCZTO-based compositions. A maximum elastocaloric cooling of 1.17K (298K) was achieved for an applied stress of 0-200MPa (3kVmm(-1)). Finally, a new component of the electric-field-driven caloric effect is reported as the inverse piezocaloric effect, with a maximum temperature change of 0.4K (298K).