Magnetization processes in electrodeposited NiFe/Cu multilayered nanowires

The effect of the magnetic anisotropy and the dipolar interactions between NiFe magnetic layers and between nanowires on the magnetic properties of NiFe/Cu multilayered nanowire arrays electrodeposited into the nanopores of anodic aluminium oxide (AAO) templates with diameters of 35 and 200 nm has been studied. The variation of the aspect ratio (thickness/diameter) between the NiFe magnetic and Cu nonmagnetic layers influences the effective anisotropy field. The correlation between the measured hysteresis loops, with the applied field parallel and perpendicular to the multilayered nanowires’ axis, and the calculated effective anisotropy field,Heff, and saturation field,Hsat, shows that it is possible to tune the orientation of the magnetization axis with high accuracy. Two formulas, which include both the intra- and internanowire interactions, were proposed to calculate the saturation fields of multilayered nanowire arrays for the applied field parallel and perpendicular to the nanowires’ axis.