Changes in relative permeability and domain structures of Fe-C/Ni-Fe multilayered films with the insertion of nonmagnetic BN layers

Fe-C/Ni-Fe multilayered films have a pattern of stripes 10 or 20 μm wide. Their magnetic properties and domain structures are examined. For certain film geometries, insertion of nonmagnetic BN layers eliminates 90° closure domains in the stripe-patterned Fe-C/Ni-Fe films. The disappearance of the closure domains increases the relative permeability of the films. The stripes, with a width of 10 or 20 μm, display a relative permeability of 1500 and 1700, respectively, when closure domains have disappeared.