(1. 桂林電子科技大學(xué) 材料科學(xué)與工程學(xué)院，桂林 541004；
2. 桂林電子科技大學(xué) 廣西信息材料重點(diǎn)實(shí)驗(yàn)室，桂林 541004)
摘 要: 采用固相法制備添加K0.5Na0.5NbO3(KNN)和BBS玻璃(BBS)的BaTiO3電容器陶瓷。借助X射線衍射儀、掃描電鏡和阻抗分析儀研究摻雜對(duì)晶體結(jié)構(gòu)、微觀組織及介電性能的影響。結(jié)果表明：?jiǎn)为?dú)添加KNN的樣品呈單一的鈣鈦礦結(jié)構(gòu)。隨KNN的增加，陶瓷樣品高溫端的電容變化率減小。摻雜3%~5%KNN(摩爾分?jǐn)?shù))陶瓷滿足X7R特性。摻雜1%BBS(質(zhì)量分?jǐn)?shù))對(duì)含3%KNN(摩爾分?jǐn)?shù))陶瓷的晶體結(jié)構(gòu)無(wú)影響。BBS超過(guò)3%(質(zhì)量分?jǐn)?shù))時(shí)，有第二相Bi4B2O9和BaTi5O11生成。1 100 ℃燒結(jié)摻雜3%BBS(質(zhì)量分?jǐn)?shù))和1%KNN(摩爾分?jǐn)?shù))的BaTiO3陶瓷具有中等介電常數(shù)(1 045)，低的介電損耗(0.74%)和較高的體積電阻率(5.5×1011 Ω∙cm)，在−55、125和150 ℃的電容變化率分別為−6.6%、−1.7%和−13.2%，有望用于中溫制備的X8R型多層陶瓷電容器。
關(guān)鍵字: 鈦酸鋇；摻雜；微結(jié)構(gòu)；介電性能；多層陶瓷電容器
（1. School of Materials Science and Engineering, Guilin University of Electronic Technology, Guilin 541004, China;
2. Guangxi Key Laboratory of Information Materials, Guilin University of Electronic Technology, Guilin 541004, China）
Abstract:BaTiO3 (BT) capacitor ceramics with K0.5Na0.5NbO3 (KNN) and BBS glass (BBS) were prepared by the solid state reaction route. The effects of doping KNN and BBS on the crystal structure, microstructure and dielectric properties were investigated by means of X-ray diffraction (XRD), scanning electron microscope (SEM) and impedance analyzer. The results show that KNN-doped BT ceramics exhibit pure perovskite structure. ∆C/C25℃ values at high temperature obviously decrease with increasing KNN content. 3%−5% (mole fraction) KNN-doped BT ceramics are satisfied with the EIA X7R specification. Adding 1% (mass fraction) BBS and 3% (mole fraction) KNN have no effect on the crystal structure of BT ceramic. However, the secondary phases, Bi4B2O9 and BaTi5O11, occur when BSS content is more than 3% (mass fraction). BT ceramic sample with 3%BBS (mass fraction) and 1%KNN (mole fraction) sintered at 1 100 ℃ shows medium dielectric constant (1 045), low dielectric loss (0.74%), high volume resistivity (5.5×1011 Ω∙cm). The variation of dielectric permittivity for BT-KNN ceramic compared with room temperature is about −6.6% at −55 ℃, −1.7% at 125 ℃ and −13.2% at 150 ℃. The as-prepared ceramic material has great potential as X8R multilayer ceramic capacitors at intermediate temperature.
Key words: barium titanate; doping; microstructure; dielectric properties; multilayer ceramic capacitor
