Effects of Ag-Dopant on Dielectric Properties and Melting Behaviors of Bi_2O_3-ZnO-Nb_2O_5 (BZN)-Based Ceramics

Cubic pyrochlore structure a phase and low symmetry structure αβphase are the basic phases of BZN-based ceramics. The a phase is a congruent compound, its congruent melting point is 1190℃, corresponding to negative temperature coefficient of dielectric constant. The β phase is an incongruent compound, its incongruent melting point (peritectic temperature) is 1100℃, corresponding to positive temperature coefficient. The zero temperature coefficient of CH grade would be met with fixed α/β phase ratio. In this paper, dielectric properties of Ag-doped BZNbased α phase,β phase and CH grade diphasic ceramics were explored respectively. The results show the effects of Ag-dopant on the dielectric properties of BZN-based α phase, β phase and CH grade diphasic ceramics. The melting behaviors of Ag-doped BZN-basedβphase were explored too. The change of incongruent melting point results in the change of the dielectric property of Ag-doped BZN-based ceramics.