Publications Repository - Helmholtz-Zentrum Dresden-Rossendorf

Cylindrical magnetic nanowires are promising materials with prospects to be used in a wide range of applications. The versatility of these nanostructures is based on the tunability of their magnetic properties by the appropriate selection of the composition and morphology. In addition, stochastic behaviour has attracted attention for the development of neuromorphic devices relying on probabilistic magnetization switching. Here, we present a study of the magnetization reversal process in multisegmented CoNi/Cu nanowires. Non-standard 2D magnetic maps, recorded under in-plane magnetic field produces datasets which are correlated with the magnetoresistance measurements and micromagnetic simulations. From this, the contribution of the individual segments to the demagnetization process can be distinguished. The results show that the magnetization reversal in these nanowires does not occur through a single Barkhausen jump but rather by multi-step switching, as individual CoNi segments in the NW undergo magnetization reversal. The existence of vortex states is confirmed by their footprint in the magnetoresistance and 2D MFM maps. In addition, the stochasticity of the magnetization reversal is analysed. On the one hand, we observe different switching fields among the segments due to a slight variation in geometrical parameters or magnetic anisotropy. On the other hand, the stochasticity is observed in a series of repetitions of the magnetization reversal processes for the same NW under the same conditions.