La_(0.67-x)Er_xSr_(0.33)MnO_3(0.00≤x≤0.20)体系的磁电特性和低温电阻率反常  

Magnetic and Electrical Features of La_(0.67-x)Er_xSr_(0.33)MnO_3 System and Anomalous Low-Temperature Resistivity Behavior

作　　者：张明玉[1] 刘宁[1] 严国清[1] 彭振生[1] 

机构地区：[1]宿州学院材料实验室,安徽宿州234000

出　　处：《中国稀土学报》2005年第1期53-57,共5页Journal of the Chinese Society of Rare Earths

基　　金：国家自然科学基金重点项目(19934003);国家重点基础研究发展规划项目(001CB610604);安徽省教育厅自然科学研究计划项目(2004kj331)资助

摘　　要：实验研究了La0.67-xErxSr0.33MnO3(x=0.00,0.10,0.20)体系的M T曲线、ρ T曲线和MR T曲线。结果发现:随掺杂量增加,体系的磁结构从长程铁磁有序向自旋团簇玻璃态过渡,极低温区出现M T曲线上翘;体系的电阻率随掺杂量的增加而增加,并出现低温极小值现象。体系磁电性质的变化来源于掺杂引起的额外磁性耦合,以及晶格畸变和局域磁矩引起的类似于磁性杂质对电子自旋散射造成的近藤效应(KondoEffect)。The system La_(0.67-x)Er_xSr_(0.33)MnO_3 (x=0.00, 0.10, 0.20) was investigated through the measurements of M-T, ρ-T and MR-T curves. The experiment results show that: with the increase of doping mount, the magnetic structure of the system transforms from long-range ferromagnetic order to cluster-spin glass state, and M-T curves turn upwards at extremely low temperature. The resistivity of the system increases with the increase of doping amount, and exhibits the minimum value at low temperature. The change of magnetic and electric properties in the system comes from extra magnetic coupling induced by the doping, lattice distortion and Kondo effect induced by local magnetic moment which is similar to that induced by the scattering of magnetic impurity for electron spin.

关 键 词：凝聚态物理 磁电特性 近藤效应 稀土 

分 类 号：O482[理学—固体物理]