溶胶-凝胶法制备(Ca_(1-x)Mg_x)SiO_3陶瓷及其微波介电性能  

Synthesis and Microwave Dielectric Properties of (Ca_(1-x)Mg_x)SiO_3 Ceramic by Sol-Gel Process

作　　者：王焕平[1] 张启龙[1] 杨辉[1] 孙慧萍[1] 

机构地区：[1]浙江大学材料与化工学院,杭州310027

出　　处：《物理化学学报》2007年第4期609-613,共5页Acta Physico-Chimica Sinica

基　　金：国家重点基础研究发展规划(863项目)(2003AA302760);浙江省重点科技计划项目(2005C21038);浙江省重大科技攻关计划项目(2006C11119)资助

摘　　要：以硝酸钙、硝酸镁、正硅酸乙酯为先驱体,利用溶胶-凝胶法合成(Ca_(1-x)Mg_x)SiO_3(x=0.1、0.2、0.3、0.4、0.5)陶瓷粉体,研究了Mg^(2+)取代Ca^(2+)对陶瓷物相组成、烧结特性以及微波介电性能的影响规律.结果表明,Mg^(2+)在CaSiO_3中的最大固溶度不超过0.2;随着Mg^(2+)对Ca^(2+)取代量的增加,陶瓷在烧结后的主晶相出现从CaSiO_3相向CaMgSi_2O_6相的转变,陶瓷的烧结特性及介电性能出现先增加后下降的趋势;当x=0.3时,陶瓷体中CaSiO_3相与CaMgSi_2O_6相共存,克服了单相CaSiO_3或CaMgSi_2O_6易成片长大的缺点,有效减少了陶瓷中残留的气孔,提高烧结体致密性.(Ca_(0.7)Mg_(0.3))SiO_3在1320℃烧结后介电常数为6.62,品质因数为36962GHz.Using Ca （NO3）2·4H2O, Mg （NOa）2 ·6H2O and Si （OC2H5）4 as precursors, （Ca1-xMgx）SiO3 powders were prepared by sol-gel method with varying x （0.1, 0.2, 0.3, 0.4, 0.5）. The phase constitution, sintering characteristic and dielectric properties of （Ca1-xMgx）SiO3 ceramics were studied. The results showed that the solubility limitation of Mg^2＋ in CaSiO3 was below 0.2 and CaSiOa phase was transformed into CaMgSi2O6 phase with substituting Ca^2＋ by Mg^2＋. When x was 0.3, the growth of grains was restrained and pores were decreased due to the coexistence of CaSiO3 and CaMgSi2O6, and then the ceramic density was enhanced. The dielectric constant and quality factor of （Ca0.7Mg0.3）SiOa ceramic sintered at 132O ℃ were 6.62 and 36962 GHz, respectively.

关 键 词：溶胶-凝胶 低介电常数 CaO—MgO—SiO2 微波介质陶瓷 

分 类 号：TQ174.1[化学工程—陶瓷工业]