High electrocaloric effects by designing B-site disorder in high-polar-entropy Pb(Sc0.25In0.25Nb0.25 Ta0.25)O3 ceramics

The electrocaloric (EC) effect in ferroelectric materials has attracted extensive attention because of its high efficiency and potential applications in chip cooling. In this work, we successfully prepared a Pb(Sc 0.25 Ta 0.25 In 0.25 Nb 0.25 )O 3 (PSINT) ceramic via a solid-state reaction method with high-polar entropy. Next, the prepared ceramics were quenched at 1050 °C for various durations. The grain size of the quenched PSINT samples initially decreased to 0.39 μm and then gradually increased to 0.61 μm with a quenching time of 50 h. X-ray diffraction (XRD) patterns of the PSINT ceramics indicate that the PSINT sample transforms from the tetragonal (pseudo-cubic) to an R-3C rhombohedral phase. The measurements of the electrocaloric effect revealed a significant adiabatic temperature change (Δ T ) of approximately 1.98 K at 60 kV cm −1 and room temperature with a quenching time of 40 h. This value is 0.5 K higher than that of untreated PSINT ceramics. Moreover, the B-site atoms of the PSINT high-polar-entropy ceramics changed from a long-range ordered phase to a disordered phase after quenching. This study provides a new technical approach for room-temperature cooling devices by designing B-site disorder in relaxor ferroelectric ceramics.