High‐Temperature Dielectrics in the BiScO ₃ –BaTiO ₃ –(K _1/2 Bi _1/2 )TiO ₃ Ternary System

Abstract

Perovskite solid solution in the (1− x )[0.4BiScO 3 –0.6BaTiO 3 ]+ x (K 1/2 Bi 1/2 )TiO 3 [BSBT–KBT x ] system was synthesized using conventional sintering and hot‐isostatic pressing. Dielectric properties of BSBT ceramics with different dopant levels of KBT were characterized as a function of temperature and frequency for potential use of high‐temperature capacitors. The BSBT ceramics with KBT exhibited high dielectric permittivities (ɛ r ) (>1700 at RT) and low dielectric loss over the temperature range from 100° to 300°C, with flat temperature coefficients of permittivity (TCɛs). In addition, BSBT ceramics with increasing KBT were observed to possess dielectric relaxation characteristics at temperatures (>RT) as observed in lead‐based relaxors. Furthermore, high energy densities, being on the order of 4.0 J/cm 3 at 220 kV/cm was observed for the BSBT–KBT20 ceramics from the electric‐field polarization behavior.