A位的Gd掺杂对La_(0.7)Sr_(0.3)MnO_3体系磁电性质的影响  

The influence of Gd doping at A site on the magnetic and electrical properties in La_(0.7)Sr_(0.3)MnO_3

作　　者：刘宁[1,2] 高贵珍[1] 童伟[3] 张裕恒 

机构地区：[1]宿州师范专科学校物理系 [2]中国科学技术大学结构分析开放实验室,合肥230026 [3]中国科学技术大学结构分析开放实验室

出　　处：《物理学报》2003年第12期3168-3175,共8页Acta Physica Sinica

基　　金：国家自然科学基金重点项目 (批准号 :1993 40 0 3 );国家重点基础研究发展规划项目 (批准号 :0 0 1CB610 60 4)资助的课题~~

摘　　要：通过实验研究了La0 7-xGdxSr0 3MnO3(x =0 0 0 ,0 10 ,0 15 ,0 2 0 ,0 30 ,0 4 0 ,0 5 0 ,0 6 0 ,0 70 )体系的M T曲线、M H曲线、红外光谱、拉曼光谱、ρ T曲线和MR T曲线 .实验结果表明 :随着Gd掺杂的增加 ,体系从长程铁磁有序向自旋团簇玻璃态和反铁磁状态转变 ,高掺杂时的输运性质在其磁背景下发生异常 .Gd掺杂引起的磁结构变化和额外的磁性耦合将导致庞磁电阻效应 .The M-T curves, M-H curves, infrared spectra, Raman spectra,ρ-T curves and MR-T curves of La 0.7-xGd xSr 0.3MnO 3 (x=0.00, 0.10, 0.15, 0.20, 0.30, 0.40, 0.50, 0.60, and 0.70) are st udied. The experimental results indicate that with increasing Gd doping, the sys tem undergoes a transition from long-range ferromagnetic order to the cluster- spin glass state and further to an antiferromagnetic order. With heavily doping content, the transport property exhibits an abnormal behavior under magnetic bac kground. The variation in magnetic structure and extra magnetic coupling caused by Gd doping lead to colossal magnetoresistance.

关 键 词：钆掺杂 红外光谱 拉曼光谱 磁结构 输运行为 庞磁电阻效应 磁性耦合 双交换作用 居里温度 

分 类 号：O484.43[理学—固体物理]