【摘要】 采用固相合成法制备了(1–x)Ba4Sm9.33Ti18O54–xCa0.61Nd0.26TiO3[(1–x)BST–xCNT]系微波介质陶瓷。探讨了组成、烧结温度对微波介质陶瓷结构、介电性能的影响。x<0.6时,(1–x)BST–xCNT陶瓷为正交结构的新型钨青铜单相。x≥0.6时,相继出现了第二相Sm2Ti2O7和钙钛矿相,最终形成钙钛矿单相。微波介质陶瓷的介电常数ε随x的增大持续升高,品质因子Qf值则先增大后迅速减小再急剧增大。1325～1350℃烧结样品的微波介电性能达到最佳:x=0时,ε=75,Qf=8985GHz,谐振频率温度系数τf=–8.2×10–6/℃;x=0.2时,ε=75,Qf=9552GHz,τf=–14.4×10–6/℃;x=1时,ε=108.9,Qf=14919GHz,τf=236.2×10–6/℃。更多还原

【Abstract】 Microwave dielectric ceramics of(1–x)Ba4Sm9.33Ti18O54–xCa0.61Nd0.26TiO3[(1–x)BST–xCNT] were prepared by solid statereaction.Effects of composition and sintering temperature on their crystal structure and microwave dielectric properties were investi-gated.A single new tungsten bronze phase was observed in the(1–x)BST–xCNT ceramics when x<0.6.A secondary phase appearedand was transformed from Sm2Ti2O7 to a perovskite phase when x≥0.6;and a single perovskite phase was formed eventually.Thedielectric constant ε increased steadily with increasing x-value,but the quality factor Qf value increased first,and decreased rapidlyand then increased sharply.Optimal dielectric properties were obtained for the samples sintered at 1 325—1 350 ℃ :ε= 75,Qf=8 985GHz,temperature coefficient of resonant frequency τf = –8.2×10–6/ ℃ for x = 0;ε=75,Qf =9 552 GHz,τf = –14.4×10–6/ ℃ for x=0.2;ε=108.9,Qf=14 919 GHz,τf = 236.2×10–6/ ℃ for x=1.更多还原