Effect of Li_2CO_3-V_2O_5 on the sintering and microwave dielectric properties of 0.6Mg_4Nb_2O_(9-0.4)SrTiO_3 composite ceramics

摘要

The effects of Li_2CO_3-V2O_5 (LV) co-doped on the sinterability, phase compositions and microwave dielectric properties of 0.6Mg_4Nb_2O_(9-0.4)SrTiO_3 composite ceramics have been investigated. All specimens were prepared by solid-state reaction method and sintered at 1050-1200℃ for 5h. With an amount LV addition, the densification sintering temperature is significantly lowed from 1300℃ to 1175℃. The non-stoichiometric compounds Sr(NbTi)O_(3+δ) and Mg_4(Nb_(1-x)Ti_x)_2O_(9-δ)were confirmed by X-ray diffraction and energy dispersive X-ray analysis. For the specimen with 1.5 wt% LV addition sintered at 1175℃ for 5 h exhibited dielectric properties: εr=20.1, Qf=10 240 GHz, τf=0.15 ppm/℃.