摘要
应用常规氧化物混合法,制备了Ca[(Li1/3Ta2/3)1-xTix](CLTT)O3-δ(0.50≥x≥0)微波介质陶瓷.X射线衍射表明,CLTT是具有正交相结构的连续固溶体,而且B位Li和Ta形成了1∶2的有序化结构.用Ti4+部分替换Li1+和Ta5+稳定了钙钛矿相,破坏了1∶2有序化结构,促进了Ca[(Li1/3Ta2/3)1-xTix]O3-δ(x=0.20,0.30)陶瓷的晶粒生长.当x组分从0增加到0.50时,微波介电常数ε从24增至48,品质因数Qf值从42000降至11000GHz,谐振频率温度系数τf也由负变正.含B2O3的Ca[(Li1/3Ta2/3)0.7Ti0.3]O3-δ陶瓷在1050℃烧结,可获得ε=35,Qf=22800GHz,τf=-4 1×10-6/℃的新型微波介质材料.
The Ca[(Li_(1/3)Ta_(2/3))_(1-x)Ti_x]O_(3-δ)(0.50≥x≥0) solid solutions are prepared by a conventional oxide mixture method to develop a microwave resonator with a low sintering temperature. It is shown that Ca(Li_(1/3)Ta_(2/3))O_(3-δ)) ceramics have orthorhombic structure with 1∶2 ordering of Li and Ta on the B-sites. The substitution of Ti^(4+) for Li^(1+) and Ta^(5+) stabilized the perovskite phase, destabilized 1∶2 ordering, and improved the grain growth of Ca[(Li_(1/3)Ta_(2/3))_(1-x)Ti_x]O_(3-δ)(x=0.20, (0.30)) ceramics. As the x composition increased from 0 to 0.50, the dielectric constant ε, increased from 24 to 48, the quality factor Qf, decreased from 42 000 to 11 000 GHz, and the temperature coefficient of resonator frequency, τ_f, increased from a negative value to a positive one. A new microwave dielectric material with ε=35, Qf=22 800 GHz, and τ_f=-4.1×10^(-6)/℃ is obtained in the Ca[(Li_(1/3)Ta_(2/3))_(0.7)Ti_(0.3)]O_(3-δ) ceramics doped with B_2O_3 sintered when temperature at 1 050 ℃.
出处
《陕西师范大学学报（自然科学版）》
CAS
CSCD
北大核心
2004年第3期54-57,共4页
Journal of Shaanxi Normal University：Natural Science Edition
基金
教育部优秀青年教师资助计划项目(2003-11)
陕西省自然科学基金资助项目(2003E17)
