掺杂中温烧结BaTiO_3陶瓷的壳－芯结构与组成、工艺的关系

RELATIONSHIP OF GRAIN CORE-GRAIN SHELL STRUCTURE AND COMPOSITION,PREPARATION OF CERAMICS BASED ON BaTi_3 FIRED AT MODERATE TEMPERATURE

研究了添加少量Ｎｂ，Ｂｉ，ＣＯ杂质及Ｂ，Ｚｎ玻璃相的ＢａＴｉＯ＿３系陶瓷介电性能与其组成、工艺及结构的关系。发现晶粒壳的Ｋ－Ｔ曲线为单峰，峰值在８０℃左右。陶瓷Ｋ－Ｔ曲线的双峰现象不随Ｎｂ，Ｂｉ添加量的增加而消失，但随Ｃｏ，Ｚｎ添加量增加或烧结温度的提高而向单峰过渡。研究结果表明Ｎｂ，Ｂｉ主要决定壳的成份，Ｃｏ可促进Ｎｂ，Ｂｉ离子向晶粒内部扩散，添加Ｚｎ，Ｃｏ或改变烧结工艺对壳的厚度及成份均有较大影响。

The relationship of dielectric properties and composition,preparation and structure of BaTIO_3doped with Nb,Bi,Co as modifiers and B,Zn as flux was investigated.It is found that the K-Tcurve of grainshell has only one peak at about 80℃, The double-peak of K-T curve of the ceramics will never disappear whenthe amount of Nb, Bi is increased but will gradually become a single-peak as the amount of Co,Zn is increasedor when the sintering temperature is too high.The results show that,despite the fact that the composition ofgrain shell is mainly determined by Nb Bi,the thickness as well as the composition of grain shell are greatly influenced by the firing technique and the amount of Zn and Co which helps Nb and Bi diffuse into the grain.