Unidirectional Magnetization Relaxation in Exchange-Biased Films

Author

Mewes, T. ; Stamps, R.L. ; Lee, H. ; Edwards, E. ; Bradford, M. ; Mewes, C.K.A. ; Tadisina, Z. ; Gupta, S.

Author_Institution

Dept. of Phys. & Astron., Univ. of Alabama, Tuscaloosa, AL, USA

Volume

1

fYear

2010

fDate

7/2/1905 12:00:00 AM

Firstpage

3500204

Lastpage

3500204

Abstract

The magnetization relaxation of thin ferromagnetic Ni₈₁Fe₁₉ films in close proximity and in direct contact with antiferromagnetic FeMn films was investigated using broadband ferromagnetic resonance. For unbiased films, a contribution to the effective-damping parameter α_eff inversely proportional to the ferromagnetic film thickness is found, consistent with the presence of spin pumping. For biased films, we find a unidirectional contribution to the effective-damping parameter, which does not scale with the inverse film thickness. The unidirectional character of the magnetization relaxation is described in terms of two-magnon scattering.

Keywords

antiferromagnetic materials; exchange interactions (electron); ferromagnetic materials; ferromagnetic relaxation; ferromagnetic resonance; iron alloys; magnetic thin films; magnetisation; magnons; nickel alloys; antiferromagnetic films; damping parameter; exchange-biased films; ferromagnetic resonance; ferromagnetic thin films; spin pumping; two-magnon scattering; unidirectional magnetization relaxation; Antiferromagnetic materials; Copper; Damping; Frequency dependence; Magnetic field measurement; Magnetic resonance; Magnetization; Physics; USA Councils; Volume relaxation; Magnetodynamics; damping; exchange bias; ferromagnetic resonance; nanomagnetics;

fLanguage

English

Journal_Title

Magnetics Letters, IEEE

Publisher

ieee

ISSN

1949-307X

Type

jour

DOI

10.1109/LMAG.2010.2055552

Filename

5550119