The Phase Transition and Dielectric Performance of BiNbO₄ Ceramics Prepared by a Citrate Method

Abstract

BiNbO4 have been successfully prepared by a citrate method using home-made water-soluble Nb-citrate-peroxide. Pure β-BiNbO4 powders are obtained at 700˚C and 1050˚C respectively, and observed the abnormal phase transition from low temperature β to α phase. Compared to BiNbO4 powders, the ceramic samples have residual Bi5Nb3O15 phase under the same calcination condition, which results in the existence of pores and locally abnormal grain growth in ceramics. The ceramics calcined at 1000˚C and 1050˚C have denser structures and smaller change of dielectric performance versus frequency and temperature. The dielectric permittivity and dielectric loss of BiNbO4 ceramics calcined at 1000˚C and 1050˚C are 44, 0.026 and 35, 0.018 at 1 MHz respectively.