Cylindrical magnetic nanowires are promising materials that have the potential to be used in a wide range of applications. The versatility of these nanostructures is based on the tunability of their magnetic properties, which is achieved by appropriately selecting their composition and morphology. In addition, stochastic behavior has attracted attention in 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. Nonstandard 2D magnetic maps, recorded under an in-plane magnetic field, produce datasets that correlate with magnetoresistance measurements and micromagnetic simulations. From this process, 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 multistep switching, as individual CoNi segments in the NW undergo a 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.
|Original language||English (US)|
|State||Published - Jun 8 2022|
Bibliographical noteKAUST Repository Item: Exported on 2022-06-17
Acknowledgements: This work was carried out under the financial support of the Spanish Ministry of Innovation and Science under project PID2019-108075RB-C31/AEI/10.13039/501100011033; and the Regional Government of Madrid under project P2018/NMT-4321 NANOMAGCOST. J.M.-M. acknowledges the Spanish Ministries of Science, Innovation and Universities through FPU Program No. FPU18/01738. J.A.F.-R. acknowledges the support of the Alexander von Humboldt Foundation. R.P., C.B. (Craig Barton) and O.K. acknowledge the support of the U.K. government department for Business, Energy, and Industrial Strategy through NMS funding (low-loss electronics) and the U.K. national Quantum Technologies program.