PbO-Na_2O-Nb_2O_5-SiO_2系复合玻璃陶瓷的结晶行为和介电性能  

Crystallization and dielectric properties of PbO-Na_2O-Nb_2O_5-SiO_2 composite glass-ceramics

作　　者：王磊[1] 张庆猛[1] 杜军[1] 

机构地区：[1]北京有色金属研究总院,北京100088

出　　处：《功能材料》2010年第8期1481-1484,共4页Journal of Functional Materials

基　　金：国家高技术研究发展计划(863计划)资助项目(2008AA03A236)

摘　　要：通过熔融-快冷-可控结晶技术,制备了不同Pb含量的PbO-Na2O-Nb2O5-SiO2系的玻璃陶瓷,并对其结晶行为和介电性能进行了研究。XRD分析结果表明,在750℃下热处理的样品,随Pb含量增加,相结构由立方钙钛矿演变至焦绿石相;而850℃下热处理样品,随Pb含量增加,相结构由方钙钛矿演变为钨青铜/钙钛矿两相共存;介电性能测试结果表明,750℃热处理样品介电常数随Pb含量增加而降低;850℃热处理样品趋势相反,且高Pb含量样品的介电常数温度依赖性显著。采用EDS对玻璃相内和陶瓷颗粒内部元素分布进行了分析,并采用三元系相图对结晶反应过程进行了解释,表明,不同组分和热处理条件下,析晶反应路径的不同是造成相变演化和介电性能显著不同的主要原因。Glass-ceramics having PbO-Na2O-Nb2O5-SiO2 composition with different Pb contents were prepared; their crystallization behaviour and dielectric properties were studied in this paper.XRD analysis indicates that when heat-treated at 750℃,phase composition in the glass-ceramics turned from cubic perov skite to pyrochlore with increasing Pb contents; while for glass-ceramics heated-treated at 850℃,tendency of perovskite phase turned to the co-existence of tungsten-bronze/perovskite was found.Dielectric peroperties measurement demonstrates that for samples prepared at 750℃,dielectric constant decreases with increasing Pb contents; while for samples prepared at 850℃,the tendency is the opposite.EDS analysis was carried out to analyze the distribution of different elements in the glass-ceramics,and tertiary phase diagram of PbO-Na2O-Nb2O5 composition was utilized to explain the crystallization procedure at different heat-treatment temperatures.It is found that the difference in phase evolution and dielectric properties can be attributed to the diffrence of crystallization route at 750 and 850℃

关 键 词：玻璃陶瓷 PbNb2O6 NaNbO3 介电性能 

分 类 号：TB34[一般工业技术—材料科学与工程]