Sb_(2)O_(3)掺杂对ZnO压敏陶瓷晶粒分布特性的影响

Effect of Doping Sb_(2)O_(3) on Distribution Characteristics of ZnO Varistor Ceramic Grain

改善晶粒分布的均匀性是获得高性能ZnO压敏陶瓷的重要手段之一。本文主要从平均晶粒尺寸、晶粒分布均匀性以及晶粒形状等角度研究了不同Sb_(2)O_(3)掺杂含量的ZnO压敏陶瓷试样,并应用晶粒尺寸分布不均匀系数ε和形状参数k对晶粒进行量化。结果表明:随着Sb_(2)O_(3)掺杂量的增加,试样的平均晶粒尺寸ε以及k呈现减小的趋势,晶粒尺寸分布均匀性改善,晶粒形状由细长向规整发展,这些结果也可以很好地解释试样电性能得到改善的原因。分析认为Sb_(2)O_(3)掺杂后形成的尖晶石相抑制了晶粒的异向生长,使得晶粒尺寸减小,晶粒分布均匀性以及晶粒形状得到改善,而且尖晶石相对大晶粒区晶粒生长的抑制作用比小晶粒区弱。

It is one of the important methods to obtain the ZnO varistor ceramics with high-performance by improving the distribution uniformity of grain.In this paper,ZnO varistor ceramics samples doping with different contents of Sb_(2)O_(3)were studied from several aspects such as the average grain size,distribution uniformity of grain size,and shape of grain.In addition,the non-uniform coefficient of grain size and the shape parameter were applied for quantification.The results show that with the increase of the doping content of Sb_(2)O_(3),the average grain sizes,the non-uniform coefficients of grain size,and the shape parameters of the samples decrease generally.It suggests that the distribution uniformity of grain size is improved,and the grain shapes develop from slender to regular,which can also explain the enhance of the electrical properties of the samples.According to the analysis,the spinel phase formed after doping Sb_(2)O_(3)inhibits the anisotropic growth of the crystal grains,which decreases the grain size and improves the uniform distribution and the shape of the grains.In addition,the inhibiting effect of spinel phase on the growth of grains in the large-grain region is weaker than that in the little-grain region.