Angular dependence of the magnetic properties of cylindrical diameter modulated Ni₈₀Fe₂₀ nanowires

We have investigated numerically the angular dependence of the coercivity and remanence of cylindrical diameter modulated Ni₈₀Fe₂₀ nanowires. We observed that the system always starts reversing its magnetization through the thickest segment by means of a quite complex reversal process, considering the propagation of two vortex domain walls. Furthermore, we observed a transition from vortex domain walls to coherent-mode rotation for the thinnest segment as a function of the angle in which the external magnetic field is applied. In addition, we obtained a non-monotonic behavior for the coercivity and saturation field as a function of the angle at which the external magnetic field is applied. Finally, diameter modulation is an attractive way to handle over the motion of magnetic domain walls, a phenomenon proposed as a future data storage platform.