Effect of Li_2CO_3-V_2O_5 on the sintering and microwave dielectric properties of 0.6Mg_4Nb2O_9-0.4SrTiO_3 composite ceramics

摘要

The effects of Li_2CO_3-V_2O_5 (LV) co-doped on the sinterability, phase compositions and microwave dielectric properties of 0.6Mg_4Nb2O9-0.4SrTiO_3 composite ceramics have been investigated. All specimens were prepared by solid-state reaction method and sintered at 1050-1200°C for 5h. With an amount LV addition, the densification sintering temperature is significantly lowed from 1300°C to 1175°C. The non-stoichiometric compounds Sr(NbTi)O_(3+δ)8 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°C for 5 h exhibited dielectric properties: ε_r=20.1, Qf=10 240 GHz, τ_f=0.15 ppm/°C.