Structure and magnetic properties of FeNi/Ti sputtered multilayers

The microstructure, anisotropic magnetoresistance, magnetic properties and magnetic domain structure of sputtered FeNi films and [Ti/FeNi]n (n = 2-16) multilayers were comparatively analyzed. It was found that although the grain size increases with an increase of the FeNi thickness both in the case of FeNi films and [Ti/FeNi]n multilayers, it did not exceed 25 nm. The values of anisotropic magnetoresistance for FeNi films and [Ti/FeNi]n multilayers were close to each other showing a weak dependence on the total thickness of the multilayered structure. Coercivity for multilayers was found to be smaller than the coercivity of single layer FeNi films. Despite the absence of a direct exchange interaction between FeNi neighboring layers in the [Ti/FeNi]n structures, their domain structures were found to be quite different from magnetic domains in single layer films due to stray field compensation in the multilayers. Obtained results are useful for the development of sensitive elements for small magnetic field detectors and planar inductors