Physical Review B
Longitudinal electron transport is investigated for a long-period semiconductor superlattice in the presence of a magnetic field applied along the growth direction of the superlattice. It is shown that the longitudinal magnetoresistance exhibits a complicated dependence on the magnetic-field strength. In contrast with the conventional Shubnikov-de Haas oscillations, the magnetoresistance shows periodic oscillations only in the region of low reciprocal magnetic field.
关键词:
magnetoresistance
T.He
,
B.Zhao
,
Y.Gao
,
F.Zeng
,
F.Pan
金属学报(英文版)
The Fe/Mo multilayers were prepared by electron beam evaporation,the microstructure and magnetic properties of the multilayers were studied by X-ray diffraction,vibrating-sample magnetometer(VSM) et al.The experimental results revealed that the Fe/Mo multilayers in our experimental conditions behaved magnetoresistance effect with a sharp peak on magnetoresistance(MR)ratio curve,and magnetoresistance is easily saturated at low applied magnetic fields.For[Fe(1.5nm)/Mo(10.nm)]42 multilayers,MR ratio could arrive to 0.1The antiferromagnetic interlayer coupling could be observed in some films at room temperature.The strength of the antiferromagnetic interlayer coupling J in the films is low because of the low saturation field Hs.The relationship between magnetic properties and microstructure was also discussed in this paper.
关键词:
magnetoresistance
,
null
,
null
L.Q. Pan
,
H. Qiu
,
F.P. Wang
金属学报(英文版)
Fe-O/AlOx/Fe-O tunnel junctions were prepared by reactive magnetron sputteringunder mixed working gas Ar+2%O2. The insulating AlOx layer of 1-2nm thicknesswas sputtered directly from Al2O3 target. Electrode layers were made of 80at.% ironand 20at.% oxygen. Bottom Fe-O electrode deposited on glass substrate annealedat 473K at the pressure of 3× 10-4Pa for an hour shows disparate crystalline grainstructure, lower electrical resistance and coercivity compared to the as-deposited topelectrode. Only crystalline structrure of α-Fe is observed in both electrodes. Largetunnel magnetoresistance in large Fe-O/AlOx/Fe-O junctions of 1cm2 is observed atroom temperature and the Ⅰ-Ⅴ characteristic curve of the junction shows that thebarrier of the junction is of high quality.
关键词:
spin-dependent
,
null
,
null
,
null
陈志高
,
陈水源
,
黄志高
,
赖恒
,
都有为
稀有金属材料与工程
用固相反应烧结法制备了多晶体材料La2/3Ca1/3MnO3(LCMO),La2/3(Ca0.5Ba0.5)1/3MnO3(LCBMO)、La2/3Ba1/3MnO3(LBMO),La2/3(Sr0.5Ba0.5)1/3MnO3(LSBMO)和La2/3Sr1/3MnO3(LSMO),测量了它们在77 K～800 K的电阻和磁电阻特性.实验发现,通过一定的工艺技术制备出的CMR材料有强烈的相界效应,在低温下有大的磁电阻,且在Tc附近存在明显的从金属态向半导体态的转变;用自旋极化电子隧道效应和靠近居里点逾渗模型较好地解释了电阻和磁电阻行为;用非绝热小极化子跃迁模型对高温的电阻特性进行拟合处理,得到了激活能;同时发现退火处理对样品的电阻率有重要的影响.
关键词:
磁电阻
,
输运特性
,
稀土
,
非绝热小极化子跃迁
孟秋敏
,
欧阳峥嵘
,
李洪强
,
石磊
低温物理学报
以Cernox-1070温度传感器为研究对象,研究了其在磁场强度0-16 T和4.2-300K温区下的磁致电阻效应.实验结果表明：CX-1070温度传感器受磁场的影响较小,在16T、4.2-300K的磁效应值为-0.19-2.38%,产生的最大测量误差为0.11K;15-50K温区为磁效应最低的温度区间,在50-300K温区4T下产生的磁效应最高;在16T、4.2K处,CX-1070与Rhodium-Iron的磁效应相差20倍,CX-1070在125-300K受磁场的影响比Rho-dium-Iron大.
关键词:
Cernox-1070温度传感器
,
强磁场
,
变温
,
磁致电阻效应
