Effect of SiO2 and B2O3 on structure and dielectric properties of Bi2O3-ZnO-Nb2O5 based ceramics

The effect of SiO2, B2O3 On structure and dielectric properties of Bi2O3-ZnO-Nb2O5 (BZN) based ceramics was investigated. The structure of B2O3 doped ceramics is still single cubic pyrochlore phase as that of the reference composition Bi1.5Zn0.5(Zn0.5Nb1.5)O-7. The structure of SiO2 doped ceramics at higher doping amount (SiO2 greater than or equal to 5% mel) can not maintain the single cubic pyrochlore and a orthorhombic BiNbO4 phase appears besides the main cubic pyrochlore phase. Doping SiO2 decreases dielectric constant and does not result dielectric loss degradation, Doping B2O3 does not make much change on the dielectric constant but degrades the dielectric loss. The results of dielectric behaviors show that SiO2 doping could be an effective method in adjusting the value of dielectric constants in BZN based dielectric ceramics.