Structure, phase evolution, and microwave dielectric properties of (Ag _0.5Bi_0.5)(Mo_0.5W_0.5)O₄ ceramic with ultralow sintering temperature

In the present work, the microwave dielectric ceramic (Ag _0.5Bi_0.5)(Mo_0.5W_0.5)O₄ was prepared by using the solid-state reaction method. (Ag_0.5Bi _0.5)(Mo_0.5W_0.5)O₄ was found to crystallize in the scheelite structure, in which Ag⁺ and Bi ³⁺ occupy the A site randomly with 8-coordination while Mo ⁶⁺ and W⁶⁺ occupy the B site with 4-coordination, at a sintering temperature above 500 °C, with lattice parameters a = b = 5.29469(2) Å and c = 11.62114(0) Å, space group I4₁/a (No. 88), and acceptable R_p = 9.38, R_wp = 11.2, and R _exp = 5.86. High-performance microwave dielectric properties, with permittivity 26.3, Q_f value 10000 GHz, and temperature coefficient +20 ppm/°C, were obtained in the sample sintered at 580 °C. Its chemical compatibility with aluminum at its sintering temperature was revealed and confirmed by both X-ray and energy dispersive spectrometer analysis. This ceramic could be a good candidate for ultralow-temperature cofired ceramics.