Structural, dielectric, electrocaloric, and energy storage properties of lead free Ba$_{0.975}$La$_{0.017}$(ZrxTi$_{0.95-x}$)Sn$_{0.05}$O$_3$ (x = 0.05; 0.20) ceramics

A-site deficient Ba$_{0.975}$La$_{0.017}$(ZrxTi$_{0.95-x}$)Sn$_{0.05}$O$_3$ (x = 0.05; 0.20) ceramics (BLaZ100xTS) were synthesized using the solid-state reaction. The microstructural study revealed a high density and low porosity in the studied ceramics. Besides, grain size lower than 1.5 micrometer was observed in the studied compounds, which is due to the incorporation of the rare earth element (lanthanum). X-ray diffraction and Raman studies revealed that BLaZ5TS and BLaZ20TS crystallize in a perovskite-type structure with tetragonal and cubic symmetry, respectively. The dielectric study showed a normal ferroelectric-paraelectric phase transition for BLaZ5TS while a diffuse phase transition is noticed for BLaZ20TS sample. The energy-storage density and the associated energy efficiency were determined from the P-E loops versus temperature and the calculated values are comparable with results obtained on BCZT systems. Furthermore, the adiabatic temperature change (Delta)T was calculated through the indirect method and a relatively high value of (Delta)T/(Delta)E = 0.2 10-6 K m/V is obtained in BLaZ5TS system. The simultaneous presence of energy storage property and electrocaloric responsivity makes this system a promising environmentally friendly candidate for application in electronic devices.