Electro- and Magneto-Transport Behavior of Template-Released Isolated Ferromagnetic Nanowires

The electrical and magnetic transport behavior of two assemblages of template-released isolated bundles of three Ni0.6Fe0.4 nanowires have been investigated using magnetoresistance (MR) measurements. The MR data were consistent with the theoretical predictions of anisotropic MR effect. Inhomogeneous magnetic structures were noticed at remanence upon removing the magnetic field. Where ~92% of the magnetic moments were aligned parallel to the nanowire's long axis at remanence in longitudinal measurements for both assembalages of nanowires. In contrast, ~65% and ~35% of the magnetic moments were aligned away from the nanowire's long axis at remanence in transverse measurements for both assemblages of wires, respectively. This indicates that there is a strong force competes with the shape anisotropy and this force can impose a magnetic alignment away from the nanowires long axis. The MR measurements showed: small and large features in the resistance profiles. The extracted field values from these features were compared with each other and with the switching fields reported in the literature that adopted the same and different investigative techniques. The angular dependence of the switching fields obtained from the large features was compared with the theoretical predictions of the curling model of domain reversal. An agreement and disagreement were, respectively, seen at small and high angles, indicating that the magnetization reversal within such wires might occur in a different complicated way. The results of this paper, predicts a difference between the magnetization reversal at the surface and the bulk of such relatively thick ferromagnetic nanowires, therefore, more studies are recommended to ascertain the results reported here.