HONG Chao, XIN Feng, ZENG Renfen, ZHANG Xiaohua
(Department of Mechanical and Electronic Engineering, Jingdezhen Ceramic Institute, Jingdezhen 333403, China)
Abstract: Microwave dielectric ceramics is one of the key basic materials for microwave communication technology. Among them, new-type perovskite microwave dielectric ceramics have attracted muchattention. In the present research, in order to adjust the temperature coefficient of resonant frequency (τf) of Ba0.6Sr0.4La4Ti4O15 , the hexagonal shift-type perovskite Ba0.6Sr0.4La4Ti4O15 and rutile TiO2 were combined together according to the proportion of 0.95:0.05. The dense ceramic samples were obtained through the conventional solid-state reaction method and crystal structures and microwave dielectric properties of these ceramics were investigated. The structural analysis indicates that all ceramic samples exhibit a hexagonal perovskite structure and form the solid solution after the two are combined. Simultaneously, the introduction of 0.05 TiO2 increases slightly dielectric constant of the material system, the Qf value maintains a high level and the τf coefficient is close to 0. The 0.95BSLT-0.05TiO2 ceramics sintered at 1550 ℃ display excellent microwave dielectric properties: er=47.4, Qf=46800 GHz, τf = -3.4 ppm/℃。
Key words: Ceramic; Hexagonal perovskites; Microwave dielectric properties; Temperature coefficient