Improvements of sintering and dielectric properties on Bi 2O 3–ZnO–Nb 2O 5 pyrochlore ceramics by V 2O 5 substitution

Abstract

The effects of V 2O 5 on the phase formation and dielectric properties of Bi 2O 3–ZnO–Nb 2O 5 (BZN) pyrochlore ceramics were investigated. With the small amount of V 2O 5 substitution (0.005≤ x≤0.05), the sintering temperatures of Bi 1.5Zn 0.5(Zn 0.5Nb 1.5− x V x )O 7 can be effectively reduced from 1000 to 840 °C while the phase structures still kept to be the pure cubic pyrochlores. The V 2O 5 seems to provide an eutectic melt below the sintering temperature to improve the sinterability. The dielectric constants decrease gradually with V 2O 5 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.