Controlling Magnetostatic Interactions in Segmented Co/Ni/Co Nanowires via Anisotropy Engineering
摘要
Segmented ferromagnetic nanowires combining materials with different magnetocrystalline anisotropies are of significant interest for spintronics and magnetic recording devices. In this work, arrays of three-segment Co/Ni/Co nanowires were synthesized via dual-bath electrochemical deposition into porous anodic alumina templates. The combination of hexagonal Co segments with high uniaxial magnetocrystalline anisotropy and face-centered cubic Ni segments dominated by shape anisotropy results in a pronounced uniaxial anisotropy of the entire structure. FORC-diagram analysis and micromagnetic modeling revealed collective magnetization reversal of all segments and an unusually low level of dipolar interactions, which is explained by the local closure of magnetic flux within the Co segments. An asymmetric switching mechanism was modeled: the Ni segment reverses abruptly as a single domain, while the Co segments switch through the formation of a complex domain structure. The results demonstrate the feasibility of controlling the magnetic properties of segmented nanostructures for spintronics applications.