Narrowing of the frequency-linewidth in structured magnetic strips: Experiment and theory

We examine the frequency-linewidth in structured magnetic materials experimentally and theoretically and show that this linewidth can decrease as the external field (or the frequency) is increased. This decrease in the frequency-linewidth occurs in many different systems and does not indicate an increase in damping at low frequencies, as has been suggested. Further, the frequency-linewidth can be very large for extended ferromagnetic films, but becomes significantly smaller for structured films that are narrower than a few microns. (c) 2005 American Institute of Physics.