Effect of copper oxide doping on electrocaloric and energy storage properties of lead free ferroelectric 0.6Ba(Zr0.2Ti0.8)O3-0.4(Ba0.7Ca0.3)TiO3 ceramics

This study highlights the effect of copper oxide (CuO) doping on electrocaloric (EC) and energy storage (ES) properties of solid state synthesised 1-x(0.6[Ba(Zr0.2Ti0.8)O-3]-0.4[(Ba0.7Ca0.3)TiO3])-xCuO (1-xBZCT-xCuO) ceramics with x = 0.005 to 0.05. The x-ray diffraction (XRD) analysis evidences the formation of impurity free 1-xBZCT-xCuO ceramics. Further, XRD, Raman and temperature dependent dielectric studies reveal that the inclusion of CuO into the BZCT lattice suppresses the morphotropic phase boundary (MPB) and reduces the tetragonality (c/a ratio) and consequently enhances the diffused phase transition (DPT) behaviour. The Curie temperature (T-c) shifted towards lower temperature, as the CuO content increases in 1-xBZCT-xCuO ceramics. Significantly, 0.995BZCT-0.005CuO ceramics demonstrated a maximum recoverable energy density (W-r) of 398 mJ/cm(3) with an efficiency of 90 % under electric field of 100 kV/cm with an excellent heat stability. Moreover, EC effect exhibited a temperature change of 1.02 K at 30 kV/cm and a responsivity of 0.03 Kcm/kV near T-c.