Phase formation, microstructure and electrical properties of BNT-SBT ceramics prepared via the solid-state combustion technique

Abstract

Lead-free ceramics of 0.6Bi0.5Na0.5TiO3-0.4Sr0.7Bi0.2TiO3 (BNT-SBT) were prepared by the solid-state combustion technique using glycine as fuel. The samples were calcined and sintered from 700 to 900 °C for 2 h and from 1100 to 1175 °C for 2 h, respectively. Their phase structure, microstructure and electrical properties were investigated. The XRD and Rietveld refinement results of the ceramic samples showed coexisting rhombohedral and tetragonal phases, with a ratio of 56:44 at a sintering temperature of 1150 °C. The average grain size and the measured density increased with increased sintering temperatures. The highest dielectric, ferroelectric and energy storage properties (ε max=3142 and tan δ max=0.041, P max=27.09 μC/cm2, W total=1.099 J/cm3, η = 81.3% and P es=1.16%) were obtained from the sample sintered at 1150 °C.