Dy和Sm部分替代La对La_(0.7)Sr_(0.3)MnO_3磁电行为的影响  

Influences of Partial Substitution Dy and Sm for La on Magnetic-Electric Behavior of La_(0.7) Sr_(0.3) MnO_3

作　　者：郭焕银[1] 刘宁[1] 童伟[2] 

机构地区：[1]宿州学院物理系,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》2005年第2期143-148,共6页Chinese Journal of Rare Metals

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

摘　　要：通过对La0 .7-xTxSr0 .3MnO3(T =Dy ,Sm)系列样品的红外透射谱,激光拉曼谱,M T曲线和ρT曲线的测量,研究了该样品的磁电行为。结果发现,随着掺入量的增加,样品的顺磁 铁磁相变温度逐渐降低,磁结构从顺磁向自旋团簇玻璃态、反铁磁状态转变,样品的磁电阻迅速增加。有趣的是在较低温度下,Dy掺杂M T曲线出现比较奇特的尖峰,而Sm掺杂M T曲线比较变化较平坦。对Dy ,Sm掺杂的作用可以用晶格效应和额外磁性的竞争来解释。By measuring infrared transmission spectra, laser Raman spectra, magnetization-temperature (M-T) curves, resistivity-temperature (ρ-T) curves of samples La_ 0.7-x T_xSr_ 0.3 MnO_3 (T=Dy, Sm), the magnetic-electric behavior of the samples were studied. The results show that with the doping content increasing, the temperature of paramagnetic-ferromagnetic transition in the samples decreases gradually, the magnetic structure changes from paramagnetic state to spin-cluster glass state and to anti-ferromagnetic state, and the magnetoresistance of the samples increases rapidly. It is interesting that at comparatively low temperature, the M-T curves of Dy doping exhibit a comparatively peculiar sharp peak, but those of Sm doping change comparatively smoothly. The function of Dy and Sm doping can be explained by the competition between lattice effect and extra magnetism.

关 键 词：稀土锰氧化物 额外磁性 晶格效应 稀土 

分 类 号：O482.54[一般工业技术—材料科学与工程]