BST–MT复相陶瓷的微观形貌和相组成分析

ANALYSIS ON MICROSTRUCTURE AND PHASE COMPONENTS OF BST-MT COMPOSITE CERAMICS

以硝酸钡、硝酸锶和钛酸丁酯为原料,采用草酸盐共沉淀法制备了钛酸锶钡(Ba0.6Sr0.4TiO3,BST)纳米粉体。用固相混合法制备了BST–钛酸镁(Ba0.6Sr0.4TiO3–MgTiO3,BST–MT)复相陶瓷。用扫描电镜观察BST纳米粉体和BST–MT复相陶瓷的形貌。通过X射线衍射分析BST纳米粉体和BST–MT复相陶瓷的相组成。结果表明:草酸盐共沉淀法合成了立方晶相的BST粉体,该纳米粉体具有较好的分散性且形貌规整。用BST粉体与MgTiO3复合所制备的BST–MT复相陶瓷由等轴状和长柱状2种晶粒组成。能谱分析结果表明:等轴状晶粒为BST,长柱状晶粒为MgTiO3;该BST–MT复相陶瓷具有良好的介电常数–温度特性。

Barium strontium titanate （Ba0.6Sr0.4TiO3） nano-powders were prepared from Ba（NO3）2, Sr（NO3）2, oxalic acid dehydrate, and tetrabutyl titanate （Ti（OC4H9）4） as raw materials by the co-precipitation method. Barium strontium titanate composites doped by magnesium titanate （BST-MT） were obtained by the traditional solid phase method. Their structures and morphology were characterized by X-ray diffraction and scanning electron microscope （SEM）. The experimental results show that the Ba0.6Sr0.4TiO3 nano-powders obtained by the aforementioned technique are well dispersed, with an orbicular morphology. The SEM results also show that the microstructure of BST-MT is composed of both orbicular and virgulate crystal grains. Further investigation by energy dispersive spectroscopy analysis shows that the orbicular grains were BST and the virgulate grains were MT. The BST-MT composites showed good dielectric constant-temperature properties.