La_(0.80)Sr_(0.05)Na_(0.15)MnO_3/xCuO复合体电输运机制及磁电阻的温度稳定性  

Electrical Transport Mechanism and Temperature Stability of Magnetoresistance in the Two-phase La_(0.80)Sr_(0.05)Na_(0.15)MnO_3/xCuO Composites

作　　者：李莉 王桂英[1,2] 毛强[1,2] 刘宁[1,3] 彭振生[1] 

机构地区：[1]自旋电子与纳米材料安徽省重点实验室,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]安徽工程大学,安徽芜湖241000

出　　处：《稀土》2014年第3期82-86,共5页Chinese Rare Earths

基　　金：国家自然科学基金重点项目资助(19934003);安徽省自然科学基金项目资助(1308085MA11);安徽省教育厅自然科学研究重点项目资助(KJ2013A245;KJ2012Z404);自旋电子与纳米材料安徽省重点实验室开放课题(2012YKF09;2012YKF10;2012YKF08)

摘　　要：用固相反应法制备了La0.80Sr0.05Na0.15MnO3/xCuO(x=0,0.05,0.10,0.15,0.20,0.30)二相复合体系,通过X射线衍射(XRD)图谱、电阻率-温度(ρ-T)曲线、ρ-T拟合曲线、磁电阻-温度(MR-T)曲线,研究了样品的电输运机制及磁电阻的温度稳定性。结果表明,在低温类金属区,电输运机制是自旋电子受单磁子散射作用,用ρ-T2拟合得很好;在较高温区MR-T曲线出现"压峰效应",是因为界面效应产生的非本征磁电阻占优势,本征磁电阻与非本征磁电阻迭加产生的磁电阻随温度变化不大;特别是x=0.05的样品,0.8 T磁场下在240 K^320K温区,磁电阻保持(9.9±0.4)%基本不随温度变化,在室温附近△T=80 K温区磁电阻的温度稳定性很好。The two-phase composite system of La0. 80Sr0. 05Na0. 15MnO3/xCuO（ x = 0,0. 05,0. 10,0. 15,0. 20,0. 30）was prepared by solid-state reaction method,and electric transport mechanism and temperature stability of magnetoresistance of the samples were studied through X-ray diffraction（ XRD） patterns,resistivity-temperature（ ρ-T） curves,ρ-T fitted curves and magnetoresistance-temperature（ MR-T） curves. The results indicate that in low-temperature metal-like area,the electric transport mechanism is the scattering function of single magneton upon spin electron,and ρ-T curves can be fitted by ρ-T^2very well; MR-T curves exhibit＂peak-suppressed effect＂in comparatively high temperature range because extrinsic magnetoresistance induced by boundary effect dominates the system,and the magnetoresistance from the addition of intrinsic magnetoresistance and extrinsic magnetoresistance were little changed with temperature; especially the magnetoresistance of the sample with x = 0. 05 in the magnetic field of 0. 8 T keeps at（ 9. 9 ± 0. 4） %,and basically does not change with temperature in the temperature range of 240-320 K. Therefore,the temperature stability of magnetoresistance is very good near room temperature（ △T = 80 K）.

关 键 词：磁电阻温度稳定性 电输运机制 钙钛矿氧化物 二相复合体 

分 类 号：O482.54[一般工业技术—材料科学与工程]