Microwave dielectric properties of low-firing BiNbO4 ceramics with V2O5 substitution

The effect of V₂O₅ substitution on the sintering behavior and the microwave dielectric properties of BiNbO₄ ceramics were studied. The sintering temperatures of Bi(V _x Nb_1?x )O₄ ceramics decrease from 990 to 810°C with x value increasing from 0.002 to 0.064. The size of grains increased with the sintering temperature increasing and decreased with the substitution amount increasing. The dielectric properties are affected by the microstructures very much. The quality factor Q value is from 2500 to 4000 at about frequency?=?5 GHz and reach to the maximum when x?=?0.032. With the different x value, the Q _f values change between 15000 to 20000 GHz; the τ _f values changes between 0 and +20 ppm/°C between temperature range 25～85°C and decreased with the increasing of x value.