Improved thermal stability of dielectric properties and energy storage properties of lead-free relaxor Ba(1-x)LaxTi0.89Sn0.11O3 ceramics

Lead-free perovskite ceramics Ba(1-x)LaxTi0.89Sn0.11O3 with x= 0, 0.015, 0.025, and 0.035 (BLTSnx) were synthesized by solid-state reaction method. The enhanced energy storage properties were studied across the ferroelectric relaxor conversion. The pure perovskite structure of all prepared samples was confirmed by X-ray diffraction (XRD) analysis and the Raman spectroscopy technique. Scanning electron microscopy micrographs show a drastic decrease in the grain size in La-doped ceramics. Furthermore, the doped samples exhibit smeared phase transition and frequency dispersion in dielectric permittivity, typical for relaxors. The P-E hysteresis loops become thin with the increase of the La-doping, demonstrating the ferroelectric-relaxor phase conversion. The enhanced recovered energy density and the energy storage efficiency of 158.8 mJ/cm3 and 82.73 % were observed in the BLTSn2.5 sample at room temperature, respectively. These properties indicate that environmentally friendly BLTSn2.5 is a viable candidate for energy-storage capacitor applications near room temperature.