Enhanced electrocaloric effect at room temperature in Mn2+ doped lead-free (BaSr)TiO3 ceramics via a direct measurement

(Ba1-xSrx)(MnyTi1-y)O-3 (BSMT) ceramics with x = 35, 40 mol% and y = 0, 0.1, 0.2, 0.3, 0.4, 0.5 mol% were prepared using a conventional solid-state reaction approach. The dielectric and ferroelectric properties were characterized using impedance analysis and polarization-electric field (P-E) hysteresis loop measurements, respectively. The adiabatic temperature drop was directly measured using a thermocouple when the applied electric field was removed. The results indicate that high permittivity and low dielectric losses were obtained by doping 0.1-0.4 mol% of manganese ions in (BaSr)TiO3 (BST) specimens. A maximum electrocaloric effect (ECE) of 2.75 K in temperature change with electrocaloric strength of 0.55 K center dot(MV/m)(-)(1) was directly obtained at similar to 21 degrees C and 50 kV/cm in Ba0.6Sr0.4Mn0.001Ti0.999O3 sample, offering a promising ECE material for practical refrigeration devices working at room temperature.

Automated summary

Doping manganese ions in (BaSr)TiO3 (BST) ceramics can lead to high permittivity and low dielectric losses, improving the performance of the materials. The Ba0.6Sr0.4Mn0.001Ti0.999O3 sample exhibited a maximum electrocaloric effect of 2.75 K in temperature change at approximately 21 degrees C and 50 kV/cm, making it a promising ECE material for practical refrigeration devices operating at room temperature.