借助典型的固相反应烧结机制,研究了MgO含量对微波高品质因数瓷介材料微观结构与介电性能参数影响的规律。结果表明:高温烧结的镁钛系瓷介质中,随着MgO含量增加,Mg 2 TiO 4晶相的含量逐渐降低、瓷体晶粒由尖晶石型演变为氯化钠型结构,对应的微波介电常数出现缓慢降低,在10.10~13.37范围连续可调。当x=16时,在1525℃/2 h烧成,可获得性能优良的(2+x)MgO-TiO2陶瓷,其ρ=3.49g·cm–3,εr=10.37,Q·f=118747 GHz(f=10.47 GHz),τf=–53.35×10–6℃–1。
The effect of MgO content on microstructure and dielectric properties of highQ ceramics were studied. Samples were prepared by solid state reaction. The results show that with the increase amount of MgO, Mg2TiO4 crystal content reduces and some particles of sodium chloride structure replace spinel ones. Corresponding with this, adjustableεr decrease slowly from 13.37 to 10.10. Sintered at 1 525℃ for 2 h, the dielectric properties of (2+x)MgO-TiO2(x=16) ceramics are more excellent:ρ=3.49 g·cm–3,εr=10.37,Q·f=118 747 GHz(f=10.47 GHz),τf=–53.35×10–6℃–1.