溶胶-凝胶法制备硼硅玻璃掺杂BST陶瓷的研究

研究了Si-B-O系玻璃掺杂对钛酸锶钡(BST)陶瓷的相结构和介电性能的影响.实验结果表明,当x(SiO_2)＞10%时,Si-B-O系玻璃掺杂BST陶瓷易出现杂相,即Ba_2TiSi_2O_8相.x(SiO_2)≤10%,Si-B-O系玻璃掺杂BST陶瓷粉体的相结构为立方钙钛矿相结构,其合成温度大于等于600 ℃,不存在第二相. Si-B-O系玻璃掺杂BST陶瓷的烧结温度低于传统工艺.Si-B-O系玻璃掺杂BST陶瓷的显微结构呈细晶结构(晶粒尺寸＜1 μm).随玻璃含量的增加,Si-B-O系玻璃掺杂BST陶瓷介电常数ε降低,介电峰变低,平坦,峰形宽化,介电损耗降低,居里温度TC向低温移动.

Preparation of Barium Strontium Titanate Ceramics Doped Si-B-O Glass by Sol-Gel Method

The effect of Si-B-O glass doping on the phase structure and dielectric properties of barium strontium titanate (BST) ceramics were researched.Experimental results showed that the diffraction peaks of secondary phase (Ba_2TiSi_2O_8) occur,with the Si-B-O glass content>10%. With contents of SiO_2 ≤10%,BST ceramic doped Si-B-O glass powders showed typical XRD patterns of perovskite polycrystalline structure formed at 600 ℃ and no secondary phase was detected.The ceramic doped Si-B-O glass samples were sintered at lower temperatures compared with the conventional barium strontium titanate ceramics.Much smaller sized grains are obtained in the BST ceramic doped Si-B-O glass samples. The dielectric permittivity and dielectric dissipation of BST ceramic doped Si-B-O glass samples generally decreased with the invrease of the amounts of Si-B-O glass.With the decreasing of grain size,the dielectric peaks of BST ceramic doped Si-B-O glass samples become lower and broader.