【摘要】 本文采用溶胶－凝胶法合成了ＬａＣｏＯ３超微粉末。Ｘ射线衍射分析表明，在５５０℃已生成了单相的ＬａＣｏＯ３，不同温度焙烧时，结构相同，均为三方晶系。实验结果表明，ＬａＣｏＯ３的平均粒径随焙烧温度的增加而明显地增加。首次研究了ＬａＣｏＯ３的电阻率随粒径的变化，发现ＬａＣｏＯ３的电阻率随粒径的增大而减小；导电活化能随粒径的减小而变小。更多还原

【Abstract】 LaCoO3 ultrafine powders were prepared by sol-gel method. XRD indicates that the single phase LaCoO3 ultra fine powders was prepared at 550℃, and have the same structure at different firing temperatures. They belong to rhombohedral system. The experiments show that the average particle diameter of LaCoO3 increases largely with the increase of firing temperatures. The change of the electrical resistivities of LaCoO3 with the particle sizes has been studied firstly. It was found that the electrical resistivities of LaCoO3 decrease with the increase of the particle diameters; the activated energies for conduction decrease with the decrease of the particle sizes.更多还原