Investigation on microwave dielectric properties of new low-loss CoZrTa2O8 ceramics

New ceramics with CoZrTa2O8 formula were prepared by conventional solid-state reaction method. The phase composition of all sintered samples was confirmed as a single phase with monoclinic wolframite structure belonged to the P2/c space group. The grain growth was analyzed through the investigation of relative density and grain size. The dielectric constant (εr) was discussed with relative density, polarizability and porosity. The quality factors (Q × f) were analyzed by considering grain growth and atomic packing fraction. The temperature coefficient of resonant frequency (τƒ) had no significant change under different sintering temperature. The typical microwave dielectric properties of CoZrTa2O8 ceramics were εr = 23.54, Q × f = 20,100 GHz, and τƒ = −8.72 ppm/°C, sintered at 1250 °C for 4 h. Considering the low dielectric loss and near-zero τƒ value, CoZrTa2O8 ceramics should be good candidates for microwave device application.