Electrocaloric and energy storage properties of Pb-free 1-x(0.6Ba(Zr0.2Ti0.8)O3-0.4(Ba0.7Ca0.3)TiO3)-x(BiTa0.5La0.5)O3 relaxor ferroelectric ceramics

This work highlights the electrocaloric (EC) and energy storage (ES) properties of 1-x(0.6Ba(Zr0.2Ti0.8)O-3-0.4(Ba0.7Ca0.3)TiO3)-x(BiTa0.5La0.5)O-3 (1-xBZCT-xBTL) ceramics with x = 0 to 0.05. The XRD studies revealed that inclusion of BTL content in BZCT does not induce any impurity phase. The peak splitting of BZCT near 2 theta = 45(degrees) and 66(degrees) confirms the presence of morphotropic phase boundary corresponding to tetragonal and rhombohedral phases. Further, the solid solution formation of BZCT-BTL has suppressed its morphotropic phase boundary behaviour. The XRD, Raman and temperature dependent dielectric studies suggest the presence of pseudocubic phase in 1-xBZCT-xBTL at higher values of x = 0.025 and 0.05. Moreover, the inclusion of BTL boosts the diffused phase transition behaviour of BZCT ceramics. Further, BTL strengthened its relaxor nature due to a reduction in grain size as evidenced from SEM analysis. It is observed that the 0.99BZCT-0.01BTL ceramics show 95% efficiency and a maximum recoverable energy density of 479 mJ/cm(3) at 100 kV/cm. Moreover, the electrocaloric temperature change and responsivity are found to be 1.06 K and 0.01 Kcm/kV near the transition temperature.