Magnetostriction of free layer in top-type and bottom-type spin-valve films

Author

Aoshima, Kenichi ; Hong, Jongill ; Kanai, Hitoshi

Author_Institution

File Memory Lab., Fujitsu Labs. Ltd., Atsugi, Japan

Volume

36

Issue

5

fYear

2000

fDate

9/1/2000 12:00:00 AM

Firstpage

3226

Lastpage

3228

Abstract

We investigated magnetostriction of a free layer in top-type and bottom-type spin valves. The magnetostriction of the free layer in the top-type spin valve increased as the thickness of free layer decreased, which can be attributed to the increase in the surface magnetic anisotropy. However, the magnetostriction of the free layer in the bottom-type spin valve exhibited no significant change with decreasing thickness of free layer, and was smaller than that of in the top-type spin valve. This difference may come from the degree of intermixing at the interface of the free layer. We confirmed by X-ray photoelectron spectroscopy that intermixing between the spacer and free layer, Cu and CoFeB respectively, can be quite different for the top-type and the bottom-type spin valves, and that the magnetostriction can be influenced by the degree of intermixing. The magnetostriction tends to be small value when intermixing is significant, as we found in the bottom-type spin valve

Keywords

X-ray photoelectron spectra; boron alloys; cobalt alloys; ferromagnetic materials; iron alloys; magnetic anisotropy; magnetic heads; magnetic thin film devices; spin valves; CoFeB-Cu; X-ray photoelectron spectroscopy; bottom-type spin-valve films; free layer; intermixing; magnetic heads; magnetostriction; surface magnetic anisotropy; top-type spin-valve films; Iron; Magnetic anisotropy; Magnetic films; Magnetic heads; Magnetostriction; Perpendicular magnetic anisotropy; Saturation magnetization; Spectroscopy; Spin valves; Superconducting magnets;

fLanguage

English

Journal_Title

Magnetics, IEEE Transactions on

Publisher

ieee

ISSN

0018-9464

Type

jour

DOI

10.1109/20.908747

Filename

908747