Sm^(3+)掺杂BaAl_(2)Si_(2)O_(8)陶瓷的结构及微波介电性能  

Structure and Microwave Dielectric Properties of Ba_(1-x)Sm_(x)Al_(2)Si_(2)O_(8) Ceramics

作　　者：肖竣文 丁士华[1] 张云 宋天秀[1] XIAO Junwen;DING Shihua;ZHANG Yun;SONG Tianxiu(School of Materials Science and Engineering,Xihua University,Chengdu 610039,China)

机构地区：[1]西华大学材料科学与工程学院,四川成都610039

出　　处：《化工技术与开发》2023年第10期1-8,15,共9页Technology & Development of Chemical Industry

基　　金：国家自然科学基金项目(51902268);四川省科技厅重点研发项目(2021YFG0235);四川省粉末冶金工程技术研究中心开放课题重点项目(SC-FMYJ2020-02);宜宾市科技计划项目(2021GY005)。

摘　　要：本文采用传统的固相反应,合成了Ba_(1-x)Sm_(x)Al_(2)Si_(2)O_(8)(x=0、0.005、0.010、0.015、0.020)微波介质陶瓷,探讨了不同的Sm^(3+)取代量对Ba_(1-x)Sm_(x)Al_(2)Si_(2)O_(8)(BAS)陶瓷的晶体结构和微波介电性能的影响。根据第一性原理计算结果,讨论了离子取代位置,比较了不同位置的形成能,结果表明Sm^(3+)取代了Ba^(2+)。实验结果表明,Sm^(3+)能有效促进BAS由六方相到单斜相的转变,x=0.02时,转化率达到97.68%,烧结温度从1475~1550℃降至1350~1400℃,提高了品质因数(Q×f值),改善了谐振频率温度系数(τ_(f))。1400℃下烧结5h的Ba_(0.985)Sm_(0.015)Al_(2)Si_(2)O_(8)陶瓷,Q×f值为33144GHz,ρ=3.334g·cm^(-3),ε_(r)=6.993,τ_(f)=-34.92×10^(-6)℃^(-1)。Ba_(1-x)Sm_(x)Al_(2)Si_(2)O_(8)(x=0,0.005,0.010,0.015,0.020)microwave dielectric ceramics were synthesized by solid-state reaction.The effects of different Sm^(3+)substitutions on the crystal structure and microwave dielectric properties of Ba_(1-x)Sm_(x)Al_(2)Si_(2)O_(8)(BAS)ceramics were investigated.According to the calculation of first principles,the ion substitution positions were discussed and the formation energy of different positions was compared.The results showed that Sm^(3+)should replace Ba^(2+).The experimental result showed that Sm^(3+)could effectively promote the transformation of BAS from hexagonal to celsian,when x=0.02,the conversion ratio reached 97.68%.The doping of Sm^(3+)reduced the sintering temperature from 1475~1550℃ to 1350~1400℃,and improved the density,quality factor(Q×f value)and temperature coefficient of resonant frequency(τ_(f)).When x=0.015,the Ba_(0.985)Sm_(0.015)Al_(2)Si_(2)O_(8) ceramics sintered at 1400℃ for 5h exhibited the Q×f value of 33144GHz,ρ=3.334g/cm^(3),ε_(r)=6.993,τ_(f)=-34.92×10^(-6)/℃.

关 键 词：钡长石 单斜相 介电性能 离子取代 

分 类 号：TQ174.1[化学工程—陶瓷工业]