Improvements of sintering and dielectric properties on Bi2O3–ZnO–Nb2O5 pyrochlore ceramics by V2O5 substitution

The effects of V2O5 on the phase formation and dielectric properties of Bi2O3–ZnO–Nb2O5 (BZN) pyrochlore ceramics were investigated. With the small amount of V2O5 substitution (0.005≤x≤0.05), the sintering temperatures of Bi1.5Zn0.5(Zn0.5Nb1.5−xVx)O7 can be effectively reduced from 1000 to 840°C while the phase structures still kept to be the pure cubic pyrochlores. The V2O5 seems to provide an eutectic melt below the sintering temperature to improve the sinterability. The dielectric constants decrease gradually with V2O5 substitution while the temperature coefficients of the samples continuously increase. The dielectric loss are in same level as that of the basic composition at the smaller substitute amount (x≤0.02) but then degraded in lower frequency when the substitution reached to x=0.05. Obvious dispersion in the dielectric constant and loss was observed as a function of frequency and temperature after the substitution.