Origin of large positive magnetoresistance in the hard-gap regime of epitaxial Co-doped ZnO ferromagnetic semiconductors

被引:32
作者
Tian, Y. F. [1 ,2 ]
Yan, Shi-shen [1 ]
Cao, Q. [1 ]
Deng, J. X. [1 ]
Chen, Y. X. [1 ]
Liu, G. L. [1 ]
Mei, L. M. [1 ]
Qiang, Y. [2 ]
机构
[1] Shandong Univ, Sch Phys, Jinan 250100, Shandong, Peoples R China
[2] Univ Idaho, Dept Phys, Moscow, ID 83844 USA
关键词
cobalt; electrical resistivity; ferromagnetic materials; hopping conduction; II-VI semiconductors; magnetic semiconductors; magnetic thin films; magnetoresistance; molecular beam epitaxial growth; semiconductor epitaxial layers; spin polarised transport; wide band gap semiconductors; zinc compounds; HOPPING REGIME; MAGNETIC SEMICONDUCTORS; EXCHANGE; CONDUCTIVITY; TRANSPORT; FILMS;
D O I
10.1103/PhysRevB.79.115209
中图分类号
T [工业技术];
学科分类号
08 ;
摘要
We studied the electrical transport properties of single-crystal epitaxial Co-doped ZnO films grown by molecular-beam epitaxy. Upon increasing temperature, transport mechanisms changed from hard-gap resistance to Efros variable range hopping. The magnetic field and the temperature dependence of magnetoresistance revealed that large positive magnetoresistance observed in the hard-gap regime originated from the shrinkage of electron wave functions. However, no sign of spin-dependent transport behavior was found.
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页数:5
相关论文
共 23 条
[21]   Magnetoresistance and anomalous Hall effect in magnetic ZnO films [J].
Xu, Qingyu ;
Hartmann, Lars ;
Schmidt, Heidemarie ;
Hochmuth, Holger ;
Lorenz, Michael ;
Schmidt-Grund, Ruediger ;
Sturm, Chris ;
Spemann, Daniel ;
Grundmann, Marius ;
Liu, Yuzi .
JOURNAL OF APPLIED PHYSICS, 2007, 101 (06)
[22]   Ferromagnetism and magnetoresistance of Co-ZnO inhomogeneous magnetic semiconductors [J].
Yan, SS ;
Ren, C ;
Wang, X ;
Xin, Y ;
Zhou, ZX ;
Mei, LM ;
Ren, MJ ;
Chen, YX ;
Liu, YH ;
Garmestani, H .
APPLIED PHYSICS LETTERS, 2004, 84 (13) :2376-2378
[23]   HOPPING TRANSPORT IN DELTA-DOPING LAYERS IN GAAS [J].
YE, QY ;
SHKLOVSKII, BI ;
ZRENNER, A ;
KOCH, F ;
PLOOG, K .
PHYSICAL REVIEW B, 1990, 41 (12) :8477-8484