【作者】 刘宜华； 张汝贞； 王成建； 岳龙强； 季刚； 栾开政； 梅良模；

【Author】 LIU Yi-hua;ZHANG Ru-zhen;WANG Cheng-jian;YUE Long-qiang;JI Gang;LUAN Kai-zheng;MEI Liang-mo Department of Physics, Shandong University, Jinan, 250100, China

【机构】 山东大学物理系；

【摘要】 在La_0.67Ca_0.33MnO₃ 烧结多晶体中进行了掺Sm 和掺Gd研究,结果发现,随着掺杂量的增加,材料的金属-绝缘体相变温度逐渐降低,对应的峰值电阻率急剧增大,居里温度逐渐下降,材料的磁电阻比迅速提高。用13%的Sm或11%的Gd替代La后,可以使材料磁电阻比提高一个数量级。对稀土掺杂的作用可以用晶格效应来解释。更多还原

【Abstract】 The doping effects of Sm and Gd in La_0.67Ca_0.33MnO₃ polycrystalline were studied. It was found that withincreasing the doping amount, the transition temperature of metal - isolator of the samples decreased monotonically,the corresponding peak resistivity increased dramatically, the Curie temperature decreased monotonically, themagnetoresistance ratio of the materials increased significantly. The substitutions of 0.13% Sm or 0.11% Gd for Laimproved the magnetoresistance ratio by an order of magnitude. These changes can be explained by the lattice effects.更多还原