Dielectric tunable properties of BaTi_4O_9-doped Ba_(0.6)Sr_(0.4)TiO_3 microwave composite ceramics

作     者：ZHANG JingJi, ZHAI JiWei, JIANG HaiTao & YAO Xi Functional Materials Research Laboratory, Tongji University, Shanghai 200092, China 

作者机构：Functional Materials Research Laboratory Tongji University Shanghai China 

出 版 物：《Science China(Technological Sciences)》 (中国科学（技术科学英文版）)

年 卷 期：2009年第52卷第1期

页      面：116-122页

核心收录：

学科分类：08[工学] 0805[工学-材料科学与工程（可授工学、理学学位）] 080502[工学-材料学] 

基　　金：Supported by the Ministry of Science and Technology of China through 973-project (Grant No. 2009CB623302) the Cultivation Fund of the Key Scientific and Techni-cal Innovation Project, Ministry of Education of China (Grant No.707024) Shanghai Committee of Science and Technology (Grant No. 07DZ22302) Shanghai Foundation Project under 06JC14070 

主　　题：tunability microwave dielectric properties composite ceramics 

摘      要：BaTi4O9-doped Ba0.6Sr0.4TiO3 (BST) composite ceramics were prepared by the conventional solid-state reaction and their structure, dielectric nonlinear characteristics and microwave dielectric properties were investigated. The secondary phase of the orthorhombic structure Ba4Ti13O30 is formed among BST composite ceramics with the increase of BaTi4O9. At the same time, a duplex or bimodal grains size distribution shows fine grains in a coarse grain matrix. The degree of frequency dispersion of dielectric permittivity below Tm is increased initially and then decreased with respect to BaTi4O9. As the BaTi4O9 content increases, the tunability of composite ceramics decreases, while the Q value increases. Inter-estingly, 70 wt% BaTi4O9-doped BST has a tunability ~4.0% (under 30 kV/cm biasing) versus a permit- tivity ~68 and quality factor ~134.1 (at ~3.2 GHz).