Electrocaloric effect with enhanced temperature stability in an interfacial polarization controlled ferroelectric laminated composite

Abstract

Abstract Research on zero-emission lead-free ferroelectric materials is fascinating in the field of solid-state refrigeration due to the observed large electrocaloric phenomenon. However, one of the challenges involved is realizing a large adiabatic temperature change ( Δ T ) over a wide temperature span. Here, a laminated ferroelectric structure with layers, having successive phase transitions covering room temperature, is proposed to overcome this problem. BaTi1−x Sn x O3 with x = 0.08, 0.12, and 0.15 compositions exhibiting the required ferroelectric Curie temperatures was chosen for the component layers. The designed interfacial polarization engineered laminated structure with 0.15/0.08/0.12 compositional layers yielded a value of adiabatic temperature change ΔT max ⩾ 0.6 °C by an indirect method using Maxwell’s thermodynamic equations over a wide temperature span (30 °C–85 °C). The observed results are correlated to the interrelated cumulative effect of reduced interfacial polarization, homogeneous electric field distribution, field-induced phase transitions, and enhanced domain switching, which are the manifestation of the designed laminated geometry.