Magnetic Anisotropy of FeCo Films Induced by Obliquely Sputtered Ru Underlayers

Author

Lu, Z. ; Fukuma, Y. ; Butler, W.H. ; Fujiwara, H. ; Mankey, G.J. ; Matsunuma, S.

Author_Institution

MINT Center, Univ. of Alabama, Tuscaloosa, AL, USA

Volume

45

Issue

10

fYear

2009

Firstpage

4008

Lastpage

4010

Abstract

The magnetic properties of Si/Ru(t nm)/Fe₉₀Co₁₀ (3.0 nm)/Ru (4.0 nm) films with obliquely sputtered Ru underlayers were studied as a function of Ru underlayer thickness (t). It was found that an obliquely sputtered Ru underlayer produces high uniaxial anisotropy in the Fe₉₀Co₁₀ layer with extremely small hysteresis in the hard axis direction. The anisotropy field can be increased by increasing Ru underlayer thickness. X-ray reflectometry showed that the interfaces of the samples were quite smooth with rms roughness as small as 0.35 nm. The high uniaxial anisotropy of the samples shows high thermal stability and endures e-beam lithography for microscopic device fabrication. We discuss the origin of this high anisotropy in terms of a magnetostatic effect arising from an anisotropic surface morphology.

Keywords

cobalt alloys; electron beam lithography; interface magnetism; iron alloys; magnetic anisotropy; magnetic hysteresis; magnetic thin films; magnetostatics; ruthenium; silicon; sputtered coatings; surface morphology; thermal stability; Si-Ru-Fe₉₀Co₁₀-Ru; X-ray reflectometry; e-beam lithography; hard axis direction; magnetic anisotropy; magnetic films; magnetic hysteresis; magnetic properties; magnetostatic effect; microscopic device fabrication; rms roughness; sputtered Ru underlayers; surface morphology; thermal stability; Multilayered media; thin films;

fLanguage

English

Journal_Title

Magnetics, IEEE Transactions on

Publisher

ieee

ISSN

0018-9464

Type

jour

DOI

10.1109/TMAG.2009.2024161

Filename

5257394