(1-x)La_(0.6)Dy_(0.1)Sr_(0.3)MnO_3/0.5x(Sb_2O_3)复合体系的电输运性质及低场磁电阻效应  

Electric Transport Property and Low-Field Magnetoresistance Effect of (1-x)La_(0.6)Dy_(0.1)Sr_(0.3)MnO_3/0.5x(Sb_2O_3) Composite System

作　　者：杨杰[1,2] 唐永刚[1,2] 王桂英[1,2] 蔡之让[1,2] 彭振生[1,3] 

机构地区：[1]自旋电子与纳米材料安徽省重点实验室(培育基地),安徽宿州234000 [2]宿州学院机械与电子工程学院,安徽宿州234000 [3]中国科学技术大学合肥微尺度物质科学国家实验室,安徽合肥230026

出　　处：《稀有金属》2011年第6期865-870,共6页Chinese Journal of Rare Metals

基　　金：国家自然科学基金重点项目(19934003);安徽省教育厅自然科学研究重点项目(KJ2011A259;KJ2009A53Z);安徽省教育厅自然科学研究项目(KJ2009B281Z;KJ2010B229;KJ2010B228)资助

摘　　要：用固相反应法制备了(1-x)La0.6Dy0.1Sr0.3MnO3/0.5x(Sb2O3)系列样品,通过电阻率-温度(ρ-T)曲线以及ρ-T拟合曲线,研究了样品的电输运性质,电输运机制及低场磁电阻效应。结果表明:所有样品在高温区表现为绝缘体导电,在低温区表现为金属导电,产生绝缘体-金属相变;在金属导电区主要是单磁子散射起作用,可以用公式ρ=ρ0+AT2拟合;所有样品在整个温区随温度降低MR持续增大,表现出低场磁电阻特征,复合样品的磁电阻(MR)与纯的La0.6Dy0.1Sr0.3MnO3的MR相比,在低温区减小,在高温区增大,对x=0.15的样品在高温区的MR大幅度提高,当B=0.2 T,T=300 K时,MR达7.79%,比纯La0.6 Dy0.1 Sr0.3 MnO3的MR增大2.6倍,有利于MR的实际应用。The sample series of（1-x）La0.6Dy0.1Sr0.3MnO3/0.5x（Sb2O3） were prepared by the solid-state reaction method,and their electric transport property,electric transport property and low-field magnetoresistance effect were studied through the measurement and fitting of resistivity-temperature（ρ-T） curves.The results indicated that all the samples exhibited insulating conduction in high-temperature range and exhibited metallic conduction in low-temperature range.So insulator-metal transition occured;single-magneton scattering plays a main part in the metallic conduction region,and the ρ-T curves could be fitted by the formula ρ=ρ0＋AT2.The magnetoresistance（MR） of all the samples increased continuously with temperature decreasing in the whole temperature range,low-field magnetoresistance effect appeared,and compared with MR of pure La0.6Dy0.1Sr0.3MnO3,that of composite samples was smaller in low-temperature range and larger in high-temperature range.MR of the sample of x=0.15 increased by a big margin in high-temperature range,its MR at T=300 K and in B=0.2 T was 7.79%,and was 2.6 times larger than that of pure La0.6Dy0.1Sr0.3MnO3.So this benefited the practical applications of MR.

关 键 词：低场磁电阻 二相复合体 钙钛矿锰氧化物 

分 类 号：O482.54[一般工业技术—材料科学与工程]