La_2/3Ca_1/3MnO₃样品的磁和电子输运性质研究

La 2/3 Ca 1/3 MnO 3 样品的磁和电子输运性质研究 Magnetic and Electronic Transport Properties in La 2/3 Ca 1/3 MnO 3 李建青 LI Jian-qing~1 1 2 3 first-author 袁松柳 YUAN Song-liu~2 1 2 3 武汉理工大学理学院 武汉理工大学理学院 School of Sciences, Wuhan University of Technology School of Sciences, Wuhan University of Technology 华中科技大学物理学系,湖北,武汉,430070 华中科技大学物理学系,湖北,武汉,430070 Department of Physics, Huazhong University of Science and Technology Department of Physics, Huazhong University of Science and Technology ,湖北,武汉,430074 ,湖北,武汉,430074 实验研究了La2/3Ca1/3MnO3 样品零磁场下的电阻率和低磁场下的磁化强度随温度的变化行为.结果表明,除了居里温度（TC）外还存在另一特征温度 Tonset,高于 Tonset的样品为典型的顺磁绝缘体,而低于 TC 的样品为典型的铁磁金属,但在Tonset和TC 之间,样品的磁化率大大偏离居里 外斯定律,同时其导电特性显示出明显的反常.对观察到的不寻常导电特性,根据铁磁金属集团在顺磁绝缘体背景上随机分布的假设,进行了分析与探讨. Temperature dependences of zero-field resistivity and low-field magnetization are measured for La 2/3 Ca 1/3 MnO 3 . The results indicate that besides the Curie temperature T C , there exists an additional characteristic temperature T onset . The sample shows typical paramagnetic insulating behavior above T onset and ferromagnetic metallic behavior below T C . But for the temperature range between T onset and T C , the large deviation of susceptibility from the Curie-Weiss law and the anomalous conductivity behavior are observed simultaneously. Based on the random distribution of ferromagnetic metallic clusters in the paramagnetic insulating background, the anomalous conductivity behavior observed for T C < T < T onset is discussed. Mn基钙钛矿 庞磁电阻效应 绝缘体金属转变 铁磁金属集团 Mn based perovskites colossal magnetoresistance insulator-metal transition ferromagnetic metallic clusters TM271 国家自然科学基金资助项目（10374032） 2005-01-01 2021-04-01 1