摘要
用溶胶-凝胶法,在乙醇溶液中以BaAc2、Sr(NO3)2、Cd(NO3)2、Ti(OC4H9)4,冰醋酸为原料制备了多层陶瓷电容器用(Ba0.7Sr0.25Cd0.05)TiO3(BSCT)纳米粉体。用热重-差示扫描量热法分析研究了由前驱体干凝胶形成纳米BSCT粉体的加热过程。用X射线衍射、比表面积测定等研究了加水量和热处理温度对BSCT纳米粉体的颗粒尺寸、物相组成和比表面积的影响。研究了凝胶温度对凝胶时间的影响。用扫描电镜和透射电镜观察了纳米BSCT粉体的形貌和颗粒尺寸。探讨了加水量、凝胶化温度和热处理温度对BSCT纳米粉体制备的影响机制。结果表明:随着加水量的增大,BSCT粉体的颗粒尺寸由大变小而后又变大,在0.015mol Ti(OC4H9)4中加水量为40mL时所制得的BSCT粉体的颗粒尺寸最小。随着凝胶化温度的升高,凝胶时间减少。随着热处理温度的升高,BSCT粉体的颗粒尺寸变大,比表面积减小,主晶相量增多,结晶度提高。BSCT纳米粉体制备的最佳工艺条件是:0.015mol Ti(OC4H9)4中加水量为40mL,pH值为3～4,凝胶化温度是65℃,热处理温度为950℃。所得到的BSCT粉体的主晶相为钙钛矿结构,其颗粒分散性好,颗粒尺寸为80nm左右,比表面积为13.64m2/g。
Nanometer powder of （Ba0.7Sr0.25Cd0.05）TiO3 （BSCT） used for a multilayer ceramic capacitor were prepared by the sol,el method from BRAc2, Sr（NO3）2, Cd（NO3）2, Ti（OC4H9）4, and ice HAc as raw materials in alcohol solution. The process of the formation of BSCT nanometer powder was studied using thermogravimetry-differential scanning calorimetry. The influence of water volume and heat treatment temperature on the particle size, material phase composition and specific surface area of the BSCT nanometer powder was investigated using X-ray diffraction and a specific surface area measurement instrument. The influence of gel temperature on the gel time was studied. The morphology and particle size of the BSCT nanometer powder were observed using a scanning electron microscope and a transmission electron microscope. The mechanism of the influence of water volume, gel temperature and heat treatment temperature on the preparation of BSCT nanometer powder was investigated. The results show that the particle size of BSCT powder begins to decrease and then increase while the water volume increased, and the particle size of BSCT powder is at its minimum level when the water volume is 40 mL [based on 0.015 mol Ti（OC4H9）4]. The gel time decreases when the gel temperature increases. The particle size of BSCT powder increases, the specific surface area decreases and the crystallinity and amount of main crystal phase increase as the heat treatment temperature increases. The obtained optimum experimental conditions are： a water volume of 40 mL [based on 0.015 mol Ti（OC4H9）4], a pH of 3-4, a gel temperature of 65 ℃, and a treatment temperature of 950 ℃. The optimal BSCT nanometer powder is obtained, in which the main crystal phase has a perovskite structure, and the dispersion property is good. The particle size is about 80 nm and the specific surface area is 13.64 m^2/g.
出处
《硅酸盐学报》
EI
CAS
CSCD
北大核心
2007年第4期425-429,共5页
Journal of The Chinese Ceramic Society
关键词
多层陶瓷电容器
溶胶-凝胶法
钛酸钡锶镉
纳米粉体
multilayer ceramic capacitor
sol-gel process
barium strontium cadmium titanate
nanometer powder
