Sinterability and microwave dielectric properties of Li_2CO_3-V_2O_5 added Mg_4Nb_20_9-CaTi0_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 Mg_4Nb_2O_9CaTiO_3 composite ceramics have been investigated. The phase compositions and microstructure were analyzed using X-ray diffraction, energy dispersive X-ray analysis and scanning electron microscopy techniques. The densillcation sintering temperature is lowed from 1275°C to 1200°C with an amount LV addition, lor the specimen with 1.5 wt% LV addition sintered at 1200°C for 5 h exhibited dielectric properties: ε_f=23, Q·f 24 000 GHz (at 7.7GHz ), τ_f=1.0 ppm°C. These properties were correlated with the formation of non-stoichiometric compound Mg_4(Nb_(1-x)Ti_x)_2O_(9-6).