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来用溶胶－凝胶法制备了系列 Ｌａ_(０．８－ｘ)Ｃａ_０．２ＭｎＯ_３钙钛矿多晶样品，用Ｘ射线衍射分析确定了样品的钙钛矿结构，用透射电子显微镜观察了样品的形貌并估算了颗粒度及粒径分布情况，用 ＰＡＲ１５５型振动样品磁强计测量了样品磁性并确定各样品的居里温度。结果表明，随焙烧温度的提高，样品的平均粒径略有增大，但居里温度的变化没有明显的规律性，对于不同温度焙烧的样品居里温度Ｔｃ随Ｌａ３＋离子空位浓度ｘ的变化表现出相似的规律性，当ｘ＞０．０３时Ｔｃ随ｘ变化不大，当ｘ＜０．０３时，Ｔｃ随ｘ的增大有明显的提高。
A series of La_ (0.8-x) Ca_0.2MnO_3 perovskite polycrystalline samples were prepared by sol-gel method. The perovskite structure of the sample was determined by X-ray diffraction. The transmission electron microscopy Morphology and particle size and particle size distribution were estimated. The magnetic properties of samples were measured by PAR155 vibrating sample magnetometer and the Curie temperature of each sample was determined. The results show that with the increase of calcination temperature, the average particle size of the sample increases slightly, but the Curie temperature has no obvious regularity. The Curie temperature Tc of calcined sample varies with the vacancy concentration x of La3 + A similar regularity, when x> 0.03 Tc with x little change, when x <0.03, Tc with x increased significantly.