Experimental study of the magnetic characteristics of nanocrystalline thin films: the role of edge effects

Magnetic characteristics and their spatial distribution of magnetron sputtered nanocrystalline NiFe thin films of various compositions were investigated by ferromagnetic resonance (FMR) and magneto-optical Kerr effect microscopy. A sharp increase in the FMR linewidth and a strong deviation of the uniaxial magnetic anisotropy field were observed near the film edges. It was shown that the observed magnetic anisotropy behavior can be explained by assuming that besides the field-induced uniaxial magnetic anisotropy an additional source of the uniaxial anisotropy near the film edges exists, with the easy axis parallel to the edges. The possible origins of this additional contribution were discussed.