摘要
用固相反应法制备了(1-x)La0.80Sr0.05K0.15MnO3/xCuO(x=0.00,0.04,0.08,0.10,0.20,0.30)二相复合体。通过X射线衍射图谱、扫描电子显微镜照片检测结构,表明形成完好的钙钛矿相和CuO相,CuO分布在钙钛矿颗粒之间,形成对钙钛颗粒的包覆。通过测量零场和加场下的电阻率-温度曲线以及磁电阻-温度曲线,研究电输运性质及磁电阻效应,结果表明,CuO复合对La0.80Sr0.05K0.15MnO3电输运和磁电阻效应影响很大。在高温区出现磁电阻峰,表现出本征磁电阻特征,在低温区随温度降低磁电阻持续增大,表现出由界面引起的隧穿磁电阻特征,总的磁电阻是本征磁电阻与隧穿磁电阻的迭加,在中间温区出现磁电阻的温度稳定性。
The two-phase composites of（1-x） La0.80Sr0.05K0.15MnO3/xCuO（x=0.00,0.04,0.08,0.10,0.20,0.30） were prepared by solid-state reaction method.Their structure was detected by X-ray diffraction and scanning electron microscope,and the result indicates that intact perovskite phase and CuO phase are formed,CuO is distributed between perovskite grains,and perovskite grains are surrounded by CuO.Electric transport property and magnetoresistance effect were studied through the measurements of resistivity-temperature（ρ-T） curves in zero field and in applied field,and of magnetoresistance-temperature（MR-T） curves,and the result indicates that the influence of composite CuO on electric transport and magnetoresistance effect of La0.80Sr0.05K0.15MnO3 is very large.Magnetoresistance peak appears in high temperature range,which is the character of intrinsic magnetoresistance;magnetoresistance increases continuously with the decrease of temperature in low temperature range,which is the character of tunneling magnetoresistance induced by grain boundary;the total magnetoresitance is the addition between intrinsic magnetoresistance and tunneling magnetoresistance;the temperature stability of magnetoresistance appears in the intermediate temperature range.
出处
《稀土》
EI
CAS
CSCD
北大核心
2013年第3期64-68,共5页
Chinese Rare Earths
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(KJ2013A245
KJ2011A259
KJ2012Z404)
宿州学院科研平台开放课题资助项目(2011YKF08
2012YKF09)
关键词
钙钛矿锰氧化物
CUO
二相复合体
电输运性质
磁电阻
perovskite manganite
CuO
two-phase composite
electric transport property
magnetoresistance
