Tuning the electrocaloric effect by tailoring phase fraction in BaTiO3-based ferroelectrics

Abstract

The giant electrocaloric effect (ECE) in ferroelectrics arouses enthusiasm on the electrocaloric refrigeration for its zero global-warming-potential. Previous studies have observed that large ECE response occurs around ferroelectric-paraelectric phase transition in BaTiO3-based ferroelectrics. However, few attention is paid to the effect of phase fraction on ECE performance. In this work, Ba1-xSrxTi0.95Sn0.05O3 ceramics which display varied phase fraction of orthorhombic and tetragonal (O and T) phase at room temperature, are developed to reveal the influence of phase fraction on the electric properties, especially ECE performance. The electrocaloric temperature change (ΔT) is enhanced in composition with equal phase fraction of O and T, which also shows excellent piezoelectric property. Intrinsically, a number of nanodomains are formed due to the incorporation of Sr2+, greatly benefiting the invertibility of domains under the electric field. It is believed that this study opens a new way for designing and understanding of ECE in BT-based ceramics.