Influence of Capping Layers on Magnetic Anisotropy in Fe/MgO/GaAs(100) Ultrathin Films

Author

Wong, P.K.J. ; Fu, Y. ; Zhang, W. ; Zhai, Y. ; Xu, Y.B. ; Huang, Z.C. ; Xu, Y.X. ; Zhai, H.R.

Author_Institution

Dept. of Electron., Univ. of York, York

Volume

44

Issue

11

fYear

2008

Firstpage

2907

Lastpage

2910

Abstract

Magnetic anisotropies of Fe/MgO/GaAs(100) hybrid structure with two different nonmagnetic capping materials, Au and MgO have been studied by ferromagnetic resonance (FMR). A uniaxial anisotropy, unexpected from the crystal structure was observed in the ultrathin films for both capping materials. Its global easy axis is along [0-11] direction while two (010) directions are equally magnetic hard regardless of the overlayer material. The in-plane uniaxial anisotropy (in-plane cubic anisotropy) of the Au capped samples is stronger (weaker) than that of the MgO capped ones within the range of t _Fe = 7.1 to 28 ML. This suggests that the MgO overlayer suppresses the uniaxial anisotropy faster than the Au overlayer.

Keywords

III-V semiconductors; crystal structure; ferrimagnetic materials; ferromagnetic resonance; gallium arsenide; iron; magnesium compounds; magnetic anisotropy; magnetic structure; magnetic thin films; FMR; Fe-MgO-GaAs; capping layers; crystal structure; ferromagnetic resonance; hybrid structure; magnetic anisotropy; nonmagnetic capping materials; overlayer material; ultrathin films; uniaxial anisotropy; Magnetic anisotropy; molecular beam epitaxy; spintronics; tunneling barrier;

fLanguage

English

Journal_Title

Magnetics, IEEE Transactions on

Publisher

ieee

ISSN

0018-9464

Type

jour

DOI

10.1109/TMAG.2008.2002195

Filename

4717809