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

Lead-free ceramics of 0.6Bi(0.5)Na(0.5)TiO(3)-0.4Sr(0.7)Bi(0.2)TiO(3) (BNT-SBT) were prepared by the solid-state combustion technique using glycine as fuel. The samples were calcined and sintered from 700 to 900 degrees C for 2 h and from 1100 to 1175 degrees 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 degrees C. The average grain size and the measured density increased with increased sintering temperatures. The highest dielectric, ferroelectric and energy storage properties (epsilon (max)=3142 and tan delta (max)=0.041, P (max)=27.09 mu C/cm(2), W (total)=1.099 J/cm(3), eta = 81.3% and P (es)=1.16%) were obtained from the sample sintered at 1150 degrees C.