IMF2017

In the present work cerium substituted ceramics sample of compositions Bi_3-xCe_xTiNbO₉ (x = 0.0 ~ 0.10) were synthesized by solid state reaction method. The crystal structure, dielectric, electrical conduction, piezoelectric and Impendence properties were systematically studied. Pure or modified Bi₃TiNbO₉ ceramics revealed the presence of only two-layer Aurivillius phase, indicating that Ce doping entered the A-site of pseudo-perovskite structure and formed solid solutions. Furthermore, Ce dopants act as a donor doping, increase the DC resistivity (1.5 × 10⁶ Ω.cm at 500 ^oC and 2.1 × 10⁵ Ω·cm at 600 ^oC)and piezoelectric properties. Bi_2.93Ce_0.07TiNbO₉ ceramics possess the optimum d 33 value (~17 pC/N) together with a high T C point (883 ^oC). The d₃₃ value of Bi_2.93Ce_0.07TiNbO₉ eramic remains ~ 13.3 pC/N after annealing at 500 ^oC. These factors suggest that the Ce doping Bi₃TiNbO₉ ceramic is a promising candidate for ultra-high temperature sensor applications. The detailed electrical properties for Ce-doping Bi₃TiNbO₉ ceramics in the high temperature region were determined using electrochemical impedance spectra. It was found that oxygen vacancies make a major contribution of both electrical conduction and dielectric relaxation.