Effects of Magnesium–Tungsten co-substitution on crystal structure and microwave dielectric properties of CaTi1-x(Mg1/2W1/2)xO3 ceramics

CaTi 1-x (Mg 1/2 W 1/2 ) x O 3 (x = 0, 0.02, 0.04, 0.06, 0.08) dielectric ceramics were synthesized via the traditional solid-state reaction method. Crystal structure and microwave dielectric properties of CaTi 1-x (Mg 1/2 W 1/2 ) x O 3 system were systematically investigated based on chemistry bond theory (P–V-L theory) for the first time. The pure perovskite phase was obtained for all doped samples, as confirmed through the XRD and Rietveld refinement results. The lattice characteristics were closely related to the microwave dielectric properties. The bond ionicity, lattice energy, and bond energy affected the dielectric constant, quality factor, and temperature stability of the ceramic material. Through the use of (Mg 1/2 W 1/2 ) 4+ doped on B-site, the CaTi 1-x (Mg 1/2 W 1/2 ) x O 3 system can maintain a high dielectric constant (ε r  > 100) while effectively reducing the τ f value from 800 ppm/ ° C to less than 300 ppm/ ° C and improving the Q × f value to 9650 GHz (at 3.76 GHz).