Mn位Ru替代对Pr_(0.5)Ca_(0.5)MnO_3电磁特性及磁电阻的影响  

EFFECT OF Ru DOPING ON Mn-SITE ON THE ELECTRICALl AND MAGNETIC PROPERTIES OF Pr_(0.5)Ca_(0.5)MnO_3

作　　者：郭宏瑞[1] 张铭[1] 严辉[1] 

机构地区：[1]北京工业大学材料科学与工程学院,北京100124

出　　处：《低温物理学报》2011年第3期174-178,共5页Low Temperature Physical Letters

基　　金：北京市属高等学校人才强教深化计划"学术创新团队建设计划"项目(PHR201007101);北京市教委科研计划(KM200910005023)资助的课题~~

摘　　要：通过对Mn位Ru替代体系Pr0.5Ca0.5Mn1-xRuxO3(0.00≤x≤0.09)的磁性及电输运机制进行研究,发现Ru元素的替代对居里温度TC、绝缘体-金属相变温度TIM有明显影响,导致了异常电输运及磁电阻行为的出现;随着Ru含量的增加,TC及TIM均向高温区移动,在外加磁场作用下,电阻率峰值被强烈压缩,从而导致了Ru掺杂x=0.005的样品在绝缘体-金属(I-M)相变温区附近极大CMR效应的出现.这些结果均显示了Mn3+与Ru4+/Ru5+之间交换作用的存在,我们的研究表明:Mn位Ru替代是一种提高和调节CMR效应的有效方法.The structural,magnetic and transport properties of polycrystalline Pr0.5Ca0.5Mn1-xRuxO3（0.00≤x≤0.09） are investigated.Replacing Mn by Ru leads to the abnormal electrical and magnetic behavior.The Curie temperature TC increases with increasing Ru concentrations,and it is worth noting that TC is much higher than the insulating-metallic（I-M） transition temperature TIM.Upon increasing Ru content TC and TIM shift to higher temperature.The substitution Ru on Mn-site induces a large decrease in the resistivity by the applying a magnetic field at the I-M transition temperature.A large magnetoresistance effect is approved,especially,at 0.5% Ru4＋ doping concentrations.Therefore,it interprets that there is an exchange interaction between Mn3＋ and Ru4＋/Ru5＋.It＇s indicated that Ru doping on Mn-site could be a promising method to enhance CMR effect.

关 键 词：掺杂 相变 CMR效应 

分 类 号：O441.6[理学—电磁学]