Synthesis, crystal structure, and microwave dielectric properties of (Mg_1-xCo_x)Ta₂O₆ solid solutions

High-dielectric-constant and low-loss ceramics in the (Mg _1-xCo_x)Ta₂O₆ solid solutions have been prepared using the conventional mixed oxide route and their microwave dielectric properties have been investigated. The X-ray diffraction patterns as well as the measured lattice parameters indicated the (Mg_1-xCo _x)Ta₂O₆ ceramics tended to form a complete solid solution with a trirutile structure. In comparison with that of simple MgTa₂O₆, an enhanced grain growth can be achieved by substituting Mg with 0.05 mol% Co. It also leads to an increase in both the ε_r and Q × f values of the ceramics. The specimen with x=0.05 possessed a combination of microwave dielectric properties: ε_r∼30.67, the Q × f∼106 200 GHz, and τ_f∼42.9 ppm/°C.