(La_(1-x)Dy_x)_(0.67)Ca_(0.33)MnO_3的磁性和磁电阻特性  

Magnetic and Magnetoresistant Properties of (La_(1-x)Dy_x)_(0.67)Ca_(0.33)MnO_3

作　　者：黄宝歆[1] 刘宜华[1] 张汝贞[1] 王成建[1] 代由勇[1] 原晓波[1] 梅良模[1] 

机构地区：[1]山东大学物理学院和晶体材料国家重点实验室,山东济南250100

出　　处：《中国稀土学报》2003年第z1期78-81,共4页Journal of the Chinese Society of Rare Earths

基　　金：国家重点基础研究专项经费资助项目(G19980613010)

摘　　要：在La0.67Ca0.33MnO3中用Dy对La进行了部分替代。结果表明,随替代量增加,材料的居里温度和相变温度单调下降,磁电阻比急剧增大。这些变化可以用稀土离子平均直径的减小和自旋团簇模型来解释。掺Dy使材料中形成大量无序自旋团簇,外加磁场使自旋团簇取向一致,从而增加了电子在团簇之间跳跃时的迁移率,产生了磁场所致的庞磁电阻效应。The Dy substituting effects for La in La_(0.67)Ca_(0.33)MnO_3 was investigated. With increasing substituting amount of Dy, the Curie temperature T_C, the phase transition temperature T_P for the samples decrease monotonically, while the corresponding CMR effect increases dramatically. These changes can be explained in terms of the decrease in average diameter of rare-earth ions and the model of spin clusters. The disordered spin clusters are induced in the samples due to the Dy doping. The magnetic field aligns the spin clusters and increases the mobility of the electron's hopping between spin clusters. This causes the magnetoresistance to change significantly.

关 键 词：庞磁电阻 (La1-xDyx)0.67Ca0.33MnO3 自旋团簇 稀土 

分 类 号：O614[理学—无机化学]