Er低掺杂(0.0≤x≤0.20)对La_(0.67)Sr_(0.33)MnO_3输运行为的影响  

INFLUENCE OF LOW Er DOPING (0.0≤x≤0.20) ON TRANSPORT BEHAVIOR IN La_(0.67)Sr_(0.33)MnO_3

作　　者：彭振生[1] 刘宁[1] 徐素军[2] 童伟[2] 

机构地区：[1]宿州师范专科学校物理系巨磁材料研究室,安徽宿州234000 [2]中国科学技术大学结构分析开放实验室,安徽合肥230026

出　　处：《低温物理学报》2004年第2期120-125,共6页Low Temperature Physical Letters

基　　金：国家自然科学基金重点项目 (项目编号 :10 3340 90 );国家重点基础研究发展规划项目 (项目编号 :0 0 1CB6 10 6 0 4 )资助的课题~~

摘　　要：通过测量M T曲线和ρ T曲线 ,研究了Er低掺杂 (0 .0≤x≤ 0 .2 0 )对La0 .6 7Sr0 .33MnO3磁电性质的影响 .发现La位被更小的稀土离子Er替代 ,居里温度Tc 和磁化强度M都会降低 ,这被认为是由于A位离子半径减小导致更大的Mn O Mn键的畸变 ,从而削弱了双交换作用 ,同时稀土离子的局域磁矩会对体系的物理性质产生作用 .在FM相主要是单磁子散射起作用 ,表现为金属型导电 ,可以用公式 ρ =ρ0 +AT2 拟合 ,但在低温下偏离了T2 关系 ,这是由于Er离子的局域磁矩对载流子散射产生较大贡献的缘故 ;By measuring M-T curves and ρ-T curves, we have studied the influence of low Er doping (0.0≤x≤0.20) on magnetic and electric properties of La-{0.67}Sr-{0.33}MnO-3. We found that the substitution for La site by a smaller rare-earth ion Er reduces both Curie temperature and magnetization, which is regarded as the result from that the decreasing of ion radius at A site causes larger distortion of Mn-O-Mn bonds and weakens double-exchange interaction. At the same time, local magnetic moment of rare-earth ion affects physical properties of the system. At FM phase, the system is dominated by single magneton scattering and shows metallic conduction which can be fitted by the formula $ρ=ρ-0+AT+2;$ While in the low temperature the resistivity behavior deviates from T+2 relation, which can be understood in terms of the significant contribution from the scattering of local magnetic moments of Er ions on carriers. The two transport properties of small polaron in PM phase and single magneton in FM phase coexist at the temperature region of phase transition.

关 键 词：铒掺杂 巨磁阻材料 单磁子 极化子 居里温度 磁化强度 锰酸锶镧 

分 类 号：TB34[一般工业技术—材料科学与工程]