络合溶胶-凝胶法制备Ba_(0.7)Sr_(0.3)TiO_3陶瓷粉体

Synthesis of Ba_(0.7)Sr_(0.3)TiO_3 ceramic powder by complex precursor route

以硝酸钡、硝酸锶、钛酸丁酯和柠檬酸为前驱体原料,采用络合溶胶-凝胶法制备出纳米级Ba0.7Sr0.3TiO3(BST)陶瓷粉体,并对材料组织结构和形貌进行了表征.结果表明:通过前驱体pH的控制可得到均匀的溶胶和凝胶.BST干凝胶经600℃热处理2 h后出现钙钛矿结构的特征峰,但伴随有BaCO3的杂质峰.当煅烧温度达到950℃时,可得到结晶良好、单相的Ba0.7Sr0.3TiO3,晶粒粒径约为80 nm.

Nano-size Ba0.7Sr0.3TiO3 ceramic powder was synthesized by complex precursor route, taken Ba（NO3）2, Sr（NO3）2, Ti（OC4 H9 ）4 and citric acid as raw materials. The precursor and powders calcined at various temperatures were characterized by Fourier transform infrared spectroscopy, X-ray diffraction and scanning electron microscopy. The results show that the uniform sol and gel were obtained by adjusting pH value without any precipitation. The crystallization of perovskite-like phase occurred at 600 ℃, with an impurity phase of BaCO3. The pure and monophasic Ba0.7Sr0.3TiO3 were prepared after the dried gel was calcimined at 950 ℃ for 2 h and the particle sizes developed around 80 nm.