具有尖晶石结构的LiFeTiO4材料的烧结与微波介电性能的研究

采用固相反应法制备了致密的LiFeTiO4陶瓷材料,并在此基础上系统地考察了其晶体结构、微结构等因素对其微波介电性能的影响.研究表明,当烧结温度合适时,能够制备出单相尖晶石结构的陶瓷,并且其烧结温度和保温时间对其物相组成和相应的微波介电性能具有明显的影响.通过实验确定了形成单相的LiFeTiO4陶瓷材料所需的临界的烧结温度和保温时间参数,并且证实了当只有烧结温度和保温时间合适时,方可得到具备良好微波介电性能的材料,即在1090 ℃烧结2 h后所制备的材料的微波介电性能为ε=16.54,Q×f=15490 GHz(8.334 GHz), τf =-60.33×10-6/ ℃.

Sintering and Microwave Dielectric Properties of LiFeTiO4 Ceramics with Spinel Crystal Structure

The synthesis characteristics of LiFeTiO4 ceramics were systematically investigated on the basis of solid-state reaction method, and crystal structures, microstructure and microwave dielectric properties were investigated for dense ceramics.It was found that single phase of LiFeTiO4 with spinel crystal structures can be obtained after the application of suitable sintering conditions, and the sintering temperature and holding time have obvious effects on the phase compositions.Critical values of sintering temperature and holding time were confirmed, for preparation of LiFeTiO4 ceramics with single phase, furthermore, ceramic materials with good dielectric properties can be obtained only when the sintering temperature and holding time had been well controlled.As the optimal sintering condition was 1090 ℃/2 h, the LiFeTiO4 ceramics have good microwave dielectric properties as ε=16.54, Q×f=15490 GHz (8.334 GHz), τf =-60.33×10-6/ ℃.