Enhanced electrocaloric response and wide temperature span in Sm-doped PMN–30PT ceramics

The electrocaloric effect (ECE) has attracted considerable attention for its promising application in next-generation solid-state cooling systems due to its high efficiency, environmental friendliness, and potential for device miniaturization. In this study, rare-earth element Sm was introduced to dope in the relaxor ferroelectric ceramics based on 0.7 Pb(Mg 1/3 Nb 2/3 )O 3 –PbTiO 3 (PMN–30PT) to enhance the ECE response and broaden the working temperature range. The Sm doping effectively enhanced the breakdown strength, reduced leakage current, and refined grain morphology was also observed, contributing to improved electrical reliability. The Sm-doped sample achieved an adiabatic temperature change of 1.38 K under an electric field of 40 kV cm −1 . Moreover, an inferred broad effective temperature span ( T span ) of 62 °C was obtained, indicating excellent wide temperature reliability. These results demonstrate that appropriate Sm doping not only enhances the EC response but also broadens its operational temperature window, offering valuable insights for the design of high-performance electrocaloric ceramics for energy-efficient and environmentally friendly solid-state cooling applications.