Ferromagnetic Resonance Spectroscopy With Very Large Precession Cone Angle in Magnetic Tunnel Junctions

Author

Moriyama, T. ; Fan, X. ; Wen, Y.Q. ; Zhang, H.W. ; Xiao, John Q.

Author_Institution

Dept. of Phys. & Astron., Univ. of Delaware, Newark, DE

Volume

45

Issue

5

fYear

2009

fDate

5/1/2009 12:00:00 AM

Firstpage

2047

Lastpage

2049

Abstract

We have developed an experimental technique to electrically characterize ferromagnetic resonance (FMR) with a large precession cone angle by using magnetic tunnel junctions on a coplanar waveguide. We observed FMR of a Ni₈₀Fe₂₀ layer as the tunneling resistance change capturing the angle between the Ni₈₀Fe₂₀ precession magnetization and a fixed magnetization in a reference electrode. The resonant frequency shifts with increasing microwave power as a result of the large precession cone angle that reduces the effective anisotropy field. We confirmed the validity of our results by the numerical simulations based on the Landau- Lifshitz-Gilbert equation.

Keywords

aluminium compounds; cobalt alloys; coplanar waveguides; ferromagnetic materials; ferromagnetic resonance; iridium alloys; iron alloys; magnetic anisotropy; magnetic tunnelling; manganese alloys; nickel alloys; IrMn-Fe₃₀Co₇₀-AlO_x-Ni₈₀Fe₂₀; Lifshitz-Gilbert equation; coplanar waveguide; effective anisotropy field; ferromagnetic resonance spectroscopy; magnetic tunnel junctions; microwave power; precession cone angle; precession magnetization; resonant frequency shifts; tunneling resistance; Ferromagnetic resonance; magnetic tunnel junctions; spintronics;

fLanguage

English

Journal_Title

Magnetics, IEEE Transactions on

Publisher

ieee

ISSN

0018-9464

Type

jour

DOI

10.1109/TMAG.2008.2002572

Filename

4816025