Ba_5Li_2W_3O_(15): A New Li-Containing Perovskite-Type Microwave Ceramic with High Q and Low τ_f

摘要

A new Li-containing microwave ceramic Ba_5Li_2W_3O_(15) with hexagonal perovskite structure was prepared through a solid-state ceramic route. Small amount of scheelite BaWO_4 appeared as a second phase during sintering. The Ba_5Li_2W_3O_(15) could be well densified at 1120℃ and exhibits good microwave dielectric properties with permittivity (ε_r) of 25.4, high Q × fvalue about 39 000 GHz, and low temperature coefficient of resonate frequency (τ_f) of 10 ppm/℃. The addition of BaCu(B_2O_5) can effectively lower the sintering temperature from 1120℃ to 900℃ and does not induce degradation of the microwave dielectric properties. These results indicate that the Ba_5Li_2W_3O_(15) ceramic might be a promising candidate in microwave dielectric resonators.