摘要
采用固相合成法制备了(Ba_(0.7)Sr_(0.3))_(4.8)(Sm_(1-β)La_β)_(8.8)Ti_(18)O_(54)(β=0.1～0.5)系列微波介质陶瓷,并对其进行了物相组成、显微结构分析和微波介电性能测试。结果表明:当β≤0.4时,(Ba_(0.7)Sr_(0.3))_(4.8)(Sm_(1-β)La_β)_(8.8)Ti_(18)O_(54)陶瓷为单相柱状的类钙钛矿钨青铜结构固溶体;当β>0.4时,陶瓷内出现第二相BaTi_6O_(13);随着La^(3+)含量的增加,陶瓷的介电常数ε_r和谐振频率温度系数τ_f单调上升,品质因数Q_f线性减小;当β=0.4时陶瓷的微波介电性能最佳,ε_r=100.23,Q_f=5 110 GHz,τ_f=19.3×10^(-6)/℃,其ε_r值远高于Ba_(6-3x)Sm_(8+2x)Ti_(18)O_(54)陶瓷的,且谐振频率温度系数近似为零。
Microwave dielectric ceramics of（Ba_（0.7）Sr_（0.3））_（4.8）（Sm_（1-β）La_β）_（8.8）Ti_（18）O_（54）（β= 0.1-0.5） were prepared by solid reaction method.The phase composition,microstructure and microwave dielectric properties were investigated.The results show that a single column solid solution with perovskite-like tungsten bronze structure was observed in（Ba_（0.7）Sr_（0.3））_（4.8）（Sm_（1-β）La_β）_（8.8）Ti_（18）O_（54） ceramics whenβ≤0.4.A secondary phase of BaTi_6O_（13） appeared whenβ0.4.The dielectric constantε_r and the temperature coefficientτ_f of resonant frequency monotonically increased with increasing La^（3＋） content.Theβ-value exhibited a negative effect on quality factor.Optimal microware dielectric properties were achieved in the ceramic as theβ=0.4 withε_r of 100.23,Q_f of 5 110 GHz andτ_f of 19.3×10^（-6）/℃.Theε_r-value of the ceramic was better than that of Ba_（6-3x）Sm_（8＋2x）Ti_（18）O_（54） ceramic.And the temperature coefficient of resonant frequency was near zero.
出处
《机械工程材料》
CAS
CSCD
北大核心
2010年第5期56-59,共4页
Materials For Mechanical Engineering
基金
国防科工委基金资助项目
关键词
微波介质陶瓷
类钙钛矿钨青铜结构固溶体
微波介电性能
microwave dielectric ceramic
perovskite-like tungsten bronze structure solid solution
microwave dielectric property
