Large cone angle magnetization precession of an individual nanopatterned ferromagnet with dc electrical detection

The on-chip resonant driving of large cone-angle magnetization precession of an individual nanoscale Permalloy element is demonstrated. Strong driving is realized by locating the element in close proximity to the shorted end of a coplanar strip waveguide, which generates a microwave magnetic field. A frequency modulation method is used to accurately measure resonant changes of the dc anisotropic magnetoresistance. Precession cone angles up to 9 degrees are determined with better than 1 degrees of resolution. The resonance peak shape is well described by the Landau-Lifshitz-Gilbert equation. (c) 2006 American Institute of Physics.