Title :
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
fDate :
5/1/2009 12:00:00 AM
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-AlOx-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;
Journal_Title :
Magnetics, IEEE Transactions on
DOI :
10.1109/TMAG.2008.2002572
