Optimization of energy storage density and efficiency in BaxSr1-xTiO3 (x ≤ 0.4) paraelectric ceramics

Paraelectric BaxSr1-xTiO3 (BST, x=0, 0.2, 0.3, 0.4) ceramics with Curie temperature far below room temperature were prepared by solid state reaction route. The effect of x value on the energy storage density and efficiency of the BST ceramics was investigated. For a given electric field, the energy storage density of BST ceramics increased, but the efficiency decreased with the increase of x value. In this work, the Ba0.3Sr0.7TiO3 ceramics possessed an optimized energy storage density (gamma=0.23 J/cm(3)) and efficiency (eta=95.7%) under the applied electric field of 90 kV/cm. Together with relatively high dielectric constant (epsilon(r)= 650 @1 kHz) and very low dielectric loss (tan delta=7.6 x 10(-4) @I kHz), the Ba0.3Sr0.7TiO3 ceramics should be more suitable for solid state compact portable pulse power electronic applications. (C) 2015 Elsevier Ltd and Techna Group S.r.l. All rights reserved.