Magnetization distribution in flat and cylindrical films subject to nonuniform hard direction fields

The magnetization distribution, resulting from the application of a nonuniform field along the hard axis of a uniaxially anisotropic thin film, is calculated. Planar and cylindrical film geometries are considered. We note 1) that there is a simple solution to the nonuniform field problem, provided the applied field is spatially periodic along the hard axis and 2) that many fields of interest are strongly localized and may be treated by the periodic calculation by assuming that the field is repeated at intervals along the hard axis. The interval is taken large enough that the resulting magnetization distribution does not depend on the periodicity so introduced. The calculation becomes invalid when appreciable saturation of magnetization occurs. Experimental measurements on plated wires and planar films, carried out for a variety of drive strap configurations using the Kerr effect probe, are in good agreement with theory.