Dynamics of magnetization reversal in a 28/spl times/4 /spl mu/m permalloy microstructure

Temporally and spatially resolved study of magnetization reversal in a 20/spl times/4 /spl mu/m, 50 nm thick permalloy sample was done using scanning Kerr microscopy. It is shown that the process starts with periodic-like instability, but then develops from both short edges towards the center. After switching the pulse field off, the initial condition is restored by creation of a domain along the long axis of the sample and gradual broadening of this domain.