Influence of V2O5 substitutions to Bi2(Zn1/3Nb2/3)2O7 pyrochlore on sintering temperature and dielectric properties

The dielectric properties of the monoclinic zirconolite-like structure compound, Bi2(Zn1/3Nb2/3−xVx)2O7 (0≤x≤0.1), were investigated. We found a small vanadium substitution (x) to Bi2(Zn1/3Nb2/3)2O7 ceramics lowered sintering temperature from 950 to 850 °C. Low-temperature sintered Bi2(Zn1/3Nb2/3−xVx)2O7 maintained high dielectric constant (εr), ∼80 and Qxf value, ∼3000 at 6 GHz. By increasing x, second phase, bismuth vanadate (Bi4V2O11) was detected. The formation of second phase is accompanied by a significant decrease in dielectric loss. It was found that Bi2(Zn1/3Nb2/3)2O7 had two phases, one was for the stoichiometric composition and the other was for Bi-deficient composition. The chemical compatibility of silver electrode and Bi2(Zn1/3Nb2/3−xVx)2O7 (x=0.005) has also been investigated using SEM micrograph and EDS line scan of the interface between a silver electrode and the ceramic body, for low-temperature cofired ceramics (LTCC) applications.