Reduced dielectric loss of modified ZnNb₂O₆ ceramics by substituting Nb⁵⁺ with Ta⁵⁺

The effects of substituting Nb⁵⁺ with Ta⁵⁺ on the microwave dielectric properties of the ZnNb₂O₆ ceramics were investigated in this study. The forming of Zn(Nb_1-xTa _x)₂O₆ (x=0-0.09) solid solution was confirmed by the measured lattice parameters and the EDX analysis. By increasing x, not only could the Q × f of the Zn(Nb_1-xTa_x) ₂O₆ (x=0-0.09) solid solution be tremendously boosted from 83 600 GHz at x=0 to a maximum 152 000 GHz at x=0.05, the highest ε_r∼24.6 could also be achieved simultaneously. It was mainly due to the uniform grain morphology and the highest relative density of the specimen. A fine combination of microwave dielectric properties (ε_r∼24.6, Q × f∼152 000 GHz at 8.83 GHz, τ_f∼-71.1 ppm/°C) was achieved for Zn(Nb _0.95Ta_0.05)₂O₆ solid solution sintered at 1175°C for 2 h.