Imaging of isolated magnetic cluster switching in thin CoCrPt films

Magnetic force microscopy is used for imaging the domains in thin nanocrystalline CoCrPt films that are part of a patterned read sensor device. The change in net magnetization has occurred in discrete local moment switching similar to Barkhausen jumps, where moments of weakly coupled grains have irreversibly rotated at fields that are lower than the bulk coercive field of the film.