Correlations between electrocaloric effect and dielectric diffuseness of lead-free Ba(Ti1-Sn )O3 ceramics

Abstract

This paper reported the correlations between electrocaloric effect (ECE) and dielectric diffuseness of Ba(Ti1-xSnx)O3 (abbreviated as BT-100xSn) ceramics. The BT-100xSn with pure perovskite structure has been synthesized by conventional solid-state reaction method. The temperature dependence of dielectric permittivity indicates that all the BT-100xSn ceramics are normal ferroelectric with diffused phase transition, and the dielectric diffuseness is strengthened as the Sn contents increase. The maximum ECE takes place in the vicinity of phase transition point, which is the characteristic of normal ferroelectrics. The BT-8Sn indicates the largest ∆T = 0.46 K and ∆T/∆E = 0.30 × 10−6 K m/V. The substitutions of Sn contents adjust the maximum ECE to different temperatures, and the good temperature-modulation of ECE is beneficial for the realization of ECE application. Considering the correlations between ECE and dielectric diffuseness, the experimental results demonstrate that the stronger dielectric diffuseness leads to the strengthened temperature stabilities of ECE but accompanied with decreased maximum ECE.