【摘要】 采用固相法制备了不同钙含量的铬酸镧试样。用扫描电镜分析了试样的微观组织 ,研究了钙含量及烧结时间对晶粒尺寸、收缩率及电阻率的影响。发现晶粒均为等轴晶 ,以台阶生长方式长大 ,随烧结时间的延长出现台阶退化现象。使用 2 0 0 0h后La0 .0 2 Ca0 .98CrO3晶粒极为致密 ,气孔聚集在晶内及晶界。钙含量的摩尔分数从 0 0 2到 0 10变化时 ,试样收缩率明显增加 ,电阻率明显下降。随烧结时间的延长 ,试样的室温电阻率变化不大。更多还原

【Abstract】 The samples of LaCrO₃ with different Ca content were prepared by solid reaction method,and the microstructure was observed by SEM.The influence of Ca content and the sintering time of LaCrO₃ to the grain size,shrinkage ratio and electrical resistivity was studied.It was found that the LaCrO₃,grains composed of equiaxed grains,grow in stage which degenerates with increasing the time.The density of La_0.02Ca_0.98CrO₃ is very high being used for 2000h,and there are pores in grains and on grain boundary.With the Ca content increasing from 0.02 to 0.1,the shrinkage ratio of the sample increases and the electrical resistivity decreases obviously.With increasing the sintering time,the change of the electrical resistivity is not obvious.更多还原