Improved Energy Storage and Electrocaloric Properties in Sm3+- and Fe3+-Substituted BCZT Ceramics

Polycrystalline ceramics with the composition 0.45BaTi0.80Zr0.20O3-0.55Ba0.69Ca0.30Sm0.01Ti0.99Fe0.01O3 were prepared using the solid-state reaction route. The phase formation of the prepared sample was confirmed by x-ray diffraction (XRD) study. The temperature-dependent dielectric permittivity (epsilon) showed a diffuse phase transition. The observance of ferroelectricity at temperatures above the Curie temperature (TC) suggests the presence of nano-polar regions in the sample. The efficiency , recoverable energy density (Wrec), and loss (Wloss) were determined from the P-E loops. The efficiency increased with an increase in temperature, while Wloss showed a reverse trend. The measured value of Wrec was 0.10 J/cm3, and a value of 94% was found for . The electrocaloric effect (ECE) was studied using the indirect method, and an adiabatic change in temperature (Delta T) of 0.34 K was found at 25 kV/cm with an electrocaloric coefficient = 0.0136 K cm kV-1. These results suggest that this composition can be used in energy storage and electrocaloric applications.