Magnetic homogeneity of the dynamic properties of (Ga,Mn)As films from the submicrometer to millimeter length scale

The diluted magnetic semiconductor (Ga,Mn)As is investigated with respect to its damping behavior using frequency dependent ferromagnetic resonance techniques. In particular we investigate the homogeneity of the spin relaxation mechanisms from a submicrometer length scale to several millimeters using time-resolved scanning Kerr microscopy in combination with ferromagnetic resonance. We find magnetic inhomogeneities on submillimeter and submicrometer length scales which lead to artificially broadened ferromagnetic resonance (FMR) lines in conventional experiments.