Spark plasma sintering temperature dependence of structural and piezoelectric properties of BNT-BT0.08 nanostructured ceramics

(Bi0.5Na0.5)TiO3 doped with 8 mol% BaTiO3 powder prepared by sol-gel was compacted and sintered by spark-plasma-sintering method. The influence of sparkplasma-sintering temperature on the densification and piezoelectric properties of these ceramics was studied. Starting from BNT-BT0.08 powder gel with a microstructure consisting of particles with average size of 50 nm, ceramics with grain size of 60-90 nm and density of about 98.9-99.6% of the theoretical density were obtained by spark-plasma-sintering at 800-900 C. Increasing the sintering temperature by SPS from 800 to 900 C lead to the increase of d33, kp, e33 T and, decrease of Qm. Typical d33 and kp values of BNT-BT0.08 ceramics sintered by sparkplasma- sintering at 900°C were 8 and 0.029, respectively.