Effect of cooling rate on loss quality of (Zr0.8Sn0.2)TiO4 ceramics with additives

Microwave dielectric properties of (Zr0.8Sn0.2)TiO4 ceramics with Sb2O5 or WO3 were investigated as a function of cooling rate. For the lattice parameters of (Zr0.8Sn0.2)TiO4, c-axis decreased with the decrease of cooling rate and reached to a minimum value at the cooling rate of 1 °C/min. The lattice parameters of the specimens with 1.0 mol% Sb2O5 or WO3 showed the similar tendency. The relative density and Qf were minimum at the specimen quenched in air, and increased with the decrease of the cooling rate. The increase of Qf values could be explained by ordering of the cations caused by the transformation at high-temperature. These results could be contributed by not only the extrinsic effect such as grain size and density but also the intrinsic effect such as the structural change with cooling rate, which could be confirmed by the IR reflectivity spectra.