La_(0.7-x)Sm_xSr_(0.3)MnO_3中的晶格效应  

Lattice Effects in La_(0.7-x)Sm_xSr_(0.3)MnO_3

作　　者：蔡之让[1] 刘宁[1] 童伟[2] 徐素军[2] 张裕恒 

机构地区：[1]宿州学院巨磁材料研究室,安徽宿州234000 [2]中国科学技术大学结构分析重点实验室,安徽合肥230026

出　　处：《稀有金属》2004年第5期847-851,共5页Chinese Journal of Rare Metals

基　　金：国家自然科学基金重点项目 ( 10 3 3 40 90 );国家重点基础研究发展规划项目 ( 0 0 1CB610 60 4)

摘　　要：研究了La0 .7-xSmxSr0 .3MnO3(x =0 .0 0 ,0 .10 ,0 .2 0 ,0 .3 0 )体系的红外光谱 ,拉曼光谱 ,M T曲线 ,ESR曲线 ,ρ T曲线和MR T曲线。实验结果表明 :随着Sm掺入量的增加 ,体系从长程铁磁有序向自旋团簇玻璃态、反铁磁态转变 ,样品的居里温度下降 ,金属 绝缘体相变温度逐渐降低 ,对应的峰值电阻渐渐增大 ,磁电阻迅速增加 ,样品物理量发生的变化可以用晶格效应来解释。The Infrared spectrum, Raman spectrum, M-T curves, ESR curves, ρ-T curves and MR-T curves of La 0.7-xSm xSr 0.3MnO 3 (x=0.00, 0.10, 0.20 and 0.30) were studied. The experimental results indicate that with increasing Sm doping, the system undergoes a transition from long range ferromagnetic order to the cluster-spin glass state and further to antiferromagnetic order, the Curie temperature decreases monotonously, the phase transition temperature of metal-isolator for the materials decreases monotonously, the corresponding peak resistance increases gradually and the magnetoresistance increases quickly. The effects of doping Sm can be explained by the lattice effect.

关 键 词：凝聚态物理 晶格效应 巨磁电阻效应 稀土 

分 类 号：O482.54[一般工业技术—材料科学与工程] TB34[理学—固体物理]