【摘要】 本文通过共沉淀工艺会成了复合氧化物Ln0.67Sr0.33MnO3(Ln=La、Pr、Nd、Sm）与传统陶瓷制各方法相比，成相温度降低约450℃．经X射线衍射分析表明，所得复合氧化物为立方钙钛矿结构，晶胞参数随稀土离子半径变化而呈规律性变化．样品的四极法电阻率测试结果表明：样品中的稀土离子Ln的离子半径对其本身的导电性起决定性的作用．应用双交换理论，只能部分地解释该实验结果．由此推测稀土离子中的4f层电子在电导过程中起一定作用．更多还原

【Abstract】 The complex oxide compounds Ln_0.67Sr_0.33MnO₃（Ln=La, Pr, Nd, Sm）were synthesized through co-precipitation route. Compared with the traditional ceramic sintering method, the temperature at which the compounds were formed were reduced by about 450℃. The X-ray powder diffraction patterns indicated that the structure of the compounds belongs to cubic perovskite type phase and their crystal unit parameters vary with the radius of rare earth ions regularly.The resistivity of samples was measured by a standard four-probe method. The results show that the radius of rare earth ion is crucial to the ability of electric conduction of the compounds. The double exchange theory can only explain our experimental results partially. The autors deduced that the electrons of 4f state of rare earth ions may play a role in electric conduction.更多还原