11Li2O-3Nb2O5-12TiO2复合微波介质陶瓷的研究*

Study of the 11Li2O-3Nb2O5-12TiO2 Microwave Dielectric Ceramic Composite*

摘要: 本文采用传统固相法制备了11Li2O-3Nb2O5-12TiO2(LNT)复合微波介质陶瓷，通过XRD、SEM分析手段，结合介电性能测试结果，探讨了烧结温度对材料相结构、介电性能的影响。结果表明，原料粉末经850℃预合成后，主要生成Li2TiO3ss以及M-phase固溶体。致密陶瓷片主要由Li2TiO3ss与M-phase固溶体两相复合组成，并没有其他相结构存在。陶瓷片中两相的组分与预合成粉末中两相的组分并不同。烧结温度达1100℃时，陶瓷片烧结致密，密度达3.76 g/cm3，相对介电常数达49，Q × f值为9482 GHz，且具有相当小的温度系数，tf = ~22 ppm/℃。

Abstract: The 11Li2O-3Nb2O5-12TiO2(LNT) microwave dielectric ceramic composites have been prepared by the solid-state reaction method. The effects of the sintering temperature on phase structure and properties were investigated by XRD, SEM and the measured dielectric properties. The calcined powders at 850˚C and the dense ceramics were mainly composed of Li2TiO3ss and M-phase solid solution. No other phase structure could be found in the dense LNT ceramics. And the compositions of two phases in the dense ceramics are different from those in the calcined powders. The LNT ceramics could be sintered densely at 1100˚C with density of about3.76g/cm3 and good microwave dielectric properties of er = 49, Q × f = 9842 GHz and tf = −22 ppm/˚C.