La_(0.67-x)Sm_xSr_(0.33)MnO_3(0.40≤x≤0.60)体系的TCR研究  

INVESTIGATION ON TCR IN La_(0.67-x)Sm_xSr_(0.33)MnO_3(0.40≤x≤0.60)

作　　者：郭焕银[1] 蔡之让[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开放实验室,安徽合肥230026

出　　处：《低温物理学报》2005年第2期130-134,共5页Low Temperature Physical Letters

基　　金：国家自然科学基金重点项目 (No .10 3340 90 );国家重点基础研究发展规划 (No .0 0 1CB6 10 6 0 4 )资助项目 .~~

摘　　要：通过测量La0 .67-xSmxSr0 .33MnO3(x =0 .4 0 ,0 .5 0 ,0 .6 0 )体系的M～T曲线和ρ～T曲线,研究了La位Sm掺杂对体系电阻温度系数(TCR)的影响.实验结果表明:Sm掺杂引起的电阻率曲线急剧变化,导致大的TCR出现;TCR在x =0 .4 0时出现峰值,随Sm掺杂的增加,TCR值逐渐减小.体系出现大的TCR ,来源于Sm掺杂引起的晶格畸变和额外磁性.By measuring M～T curves and ρ～T curves of the samples La-{0.67- x }Sm- x Sr-{0.33}MnO-3 ( x =0.40, 0.50, 0.60), the effect of Sm doping at La site on the temperature coefficient of resistance (TCR) was investigated. Experimental results show that the Sm doping causes a steep change of resistance, resulting in large TCR. TCR peak appears at x =0.40, and then the TCR decreases gradually with further increasing Sm doping level. This large TCR should result from lattice distortions and extra magnetic coupling induced by Sm+{3+} ions.

关 键 词：TCR 电阻温度系数 ρ-T曲线 电阻率曲线 晶格畸变 掺杂 SM 磁性 

分 类 号：O513[理学—低温物理]