Sr_2Fe_(1-x)Co_xMoO_6体系中Co的元素替代效应  

The element substitution effect of Co in Sr_2Fe_(1-x)Co_xMoO_6 system

作　　者：李琦[1] 贺青[1] 王杭栋[1] 杨金虎[1] 杜建华[1] 方明虎[1] 

机构地区：[1]浙江大学物理系,杭州310027

出　　处：《物理学报》2006年第11期6113-6117,共5页Acta Physica Sinica

基　　金：国家重点基础研究发展计划(937计划)(批准号:G2006CB01003)资助的课题.~~

摘　　要：在成功制备具有双钙钛矿结构Sr2Fe1-xCoxMoO6系列样品的基础上,对其结构、输运性质和磁性质进行了系统研究.结果发现,随着Co替代浓度x值的增加,样品的电阻率-温度关系由半金属行为转变为半导体行为,其室温电阻率从3.9×10-5Ω.cm增大到6.0×10-1Ω.cm;样品由亚铁磁体转变成反铁磁体,其磁相变温度TN值也随之下降;Co对Fe的部分替代使其磁电阻效应受到抑制.基于对其电子结构的分析,其磁电阻效应的起源以及Co的元素替代效应也在文中进行了讨论.The investigations on the structure, magnetic and transport Cox MoO6 samples prepared by the solid state reaction method. It properties were carried out for the double perovskite Sr2 Fe1-x is found that the relationship between resistivity and temperature changes from a typical half-metal behavior to a semiconductor behavior, with the increasing substitution concentration x value of Co for Fe. The resistivity at room temperature increases from 3.9 ×10^- 5Ω· cm （for the x = 0 sample） to 6.0 ×10^-1Ω· cm （for the x = 1.0 sample）. The magnetic order in the sample changes from a ferrimagnetic to an antiferromagnetic and the magnetic transition temperature TN decreases with the increasing Co content x. The magnetoresistance effect is depressed by the Co partial substitution for Fe. The origin of magnetoresistance and the Co substitution effect were discussed in detail based on the analysis of electronic structure of Sr2 Fe1-x Cox MoO6 system.

关 键 词：双钙钛矿结构 Sr2FeMoO6 磁电阻 

分 类 号：O482.5[理学—固体物理]