La_(0.67)Ca_(0.33)MnO_3/Zn_(0.95)Co_(0.05)O复合材料的输运特性  

Transport Properties of La_(0.67)Ca_(0.33)MnO_3/Zn_(0.95)Co_(0.05)O Composite

作　　者：庄彬[1] 赖恒[1] 陈水源[1] 林应斌[1] 黄志高[1] 

机构地区：[1]福建师范大学物理与光电信息科技学院,福建福州350108

出　　处：《福建师范大学学报（自然科学版）》2009年第5期54-57,77,共5页Journal of Fujian Normal University：Natural Science Edition

基　　金：国家重点基础研究发展计划(973)项目(2005CB623605);国家自然科学基金资助项目(60876069)

摘　　要：用溶胶凝胶法制备了Zn0.95Co0.05O包覆的La0.67Ca0.33MnO3(LCMO)纳米复合材料,研究了包覆材料对磁电阻性能的影响.实验结果表明,Zn0.95Co0.05O的表面包裹(修饰)大幅度增强了复合材料的磁电阻值;低场和高场下以及不同的温度区域内磁电阻有着不同的温度和磁场效应,意味在不同温区具有不同的磁电阻机制;采用低温隧穿磁电阻效应和逾渗模型较好地解释了实验结果.La0.67Ca0.33MnO3 composites coated Zn0.95Co0.95O were fabricated by sol-gel method. The effect of Zn0.95Co0.05O content on the magetoresistive properties of （1 - x） La0.67Ca0.33MnO3/xZn0.95Co0.05O has be experimentally investigated. It is found that the magnetoresistance of the composite is observed to be dramaticly enhanced as Zn0.95Co0.05O is coated. Moreover, there are different magnetic field dependence of magnetoresistance in different temperature ranges, which indicates the presence of different magnetoresistance mechanisms. Based on the spin-polarized tunneling model and percolation model, the experimental facts are well explained.

关 键 词：钙钛矿锰基氧化物 颗粒边界 复合材料 磁电阻 

分 类 号：O482.5[理学—固体物理]