单相Ba_2Ti_9O_(20)柠檬酸凝胶法制备、表征及介电性能  

Characterization and Dielectric Properties of Single-phase Ba_2Ti_9O_(20) Prepared by Citric Acid Gel Method

作　　者：张启龙[1] 杨辉[1] 王伟 

机构地区：[1]浙江大学纳米科学与技术中心,杭州310027

出　　处：《无机化学学报》2007年第5期817-821,共5页Chinese Journal of Inorganic Chemistry

基　　金：浙江省重大科技计划项目(No.2006C1119)。

摘　　要：采用柠檬酸凝胶法两步热处理工艺制备了单相Ba_2Ti_9O_(20)。干凝胶在750℃热处理得到了物相为BaTi_5O_(11)和Ba_4Ti1_3O_(30)、尺寸为30￣50nm的前驱体粉体。纳米前驱体具有高表面活性,促使单相Ba_2Ti_9O_(20)在1200℃热处理温度下形成。两步热处理所得的粉体比一步热处理所得的粉体具有更好的烧结和介电特性,两步热处理所得的粉体,在1250℃烧结4h,可获得理论密度为97%的Ba_2Ti_9O_(20)微波介质陶瓷,其介电性能:εr=38.5,Qf=19320GHz,τf=8.7×10-6℃-1。Single-phase Ba2Ti9O20 was prepared by citric acid gel method with two-step heat-treatment. Nanoerystalline precursor powders including BaTi5O11 and Ba4Ti13O30 of 30-50 nm were prepared by heat-treating xerogel at 750 ℃. Due to the higher surface activity of nanoerystalline precursor powder, the single-phase Ba2TigO20 can be obtained when heat treating the precursor at 1 200 ℃. The powder thus prepared had improved sintering characteristics and dielectric properties compared to those prepared by one-step heat-treatment method. When sintering the powder from two-step heat-treatment method at 1 250 ℃ for 4 h, the 97% theoretical density （TD） Ba2TigO20 could be obtained with dielectric properties of εr=38.5, Qf=19 320 GHz, and τf=8.7×10^-6 ℃^-1.

关 键 词：柠檬酸凝胶法 Ba2Ti9O20陶瓷 介电性能 

分 类 号：O614.233[理学—无机化学] O614.41[理学—化学]