Synergetic effect of BiYb_0.9Sc_0.1O₃ substitution on the energy storage performance of Ba_0.90Sr_0.10Ti_0.90Zr_0.10O₃ ferroelectric ceramic

Novel lead-free (1−x)Ba_0.90Sr_0.10Ti_0.90Zr_0.10O₃–(x)BiYb_0.9Sc_0.1O₃ (0 ≤ x ≤ 0.10) relaxor ceramic solid solutions were prepared by modified mechano-chemical activation technique with the aim of improving the energy storage properties. The Rietveld analysis of the materials indicated that all the samples show a tetragonal crystal structure with a perovskite phase. The grain morphology and density of the materials have significantly improved with BiYb_0.9Sc_0.1O₃ (BYS) substitution. The dielectric study indicates a gradual transformation from classical to relaxor dielectric with increasing BYS substitution. The ferroelectric to paraelectric transition temperature increases with increasing BYS concentration and has shown a rise of approximately 24 °C for the sample with x = 0.10 compared to the bare sample (x = 0.0). Further, the ferroelectric hysteresis loops have become significantly slimmer with a slight increase in saturation polarization, which indicates an improvement in energy storage performance of the material with BYS substitution. The optimum energy storage properties have been obtained at x = 0.06, and the sample showed a high recoverable energy density of 1.24 J cm⁻³ under the applied electric field of ±100 kV cm⁻¹. The electric field-induced bipolar strain is improved by 12% for the sample with concentration x = 0.06 compared to the bare sample. This study provides a basis for preparing BaTiO₃ based high performance ferroelectric ceramics with their potential application in pulse capacitors. (paper)