Geometry-guided vortex-to-axial magnetization switching in 3D nickel conical nanowires

Area of Science:

• Materials Science
• Nanotechnology
• Condensed Matter Physics

Background:

• Tailored 3D magnetic nanostructures are key for nanoscale magnetization control.
• Nickel conical nanowires offer a promising platform for exploring these phenomena.

Purpose of the Study:

• To fabricate vertically aligned nickel conical nanowires with controlled geometry.
• To investigate their magnetization reversal mechanisms using experiments and simulations.

Main Methods:

• Galvanostatic pulse electrodeposition into ion-track polycarbonate templates.
• Systematic variation of methanol concentration to control nanowire geometry.
• Vibrating sample magnetometry and Mumax3 micromagnetic simulations.

Main Results:

• Achieved precise control over conical geometry (diameters, aspect ratios).
• Identified vortex-like flux-closure at the base and axial alignment at the tip at remanence.
• Observed geometry-dependent reversal mechanisms: vortex stabilization in wider cones and coherent switching in narrower cones.

Conclusions:

• Nickel conical nanowires are a versatile model system for geometry-engineered magnetization dynamics.
• Demonstrated control over magnetic reversal through geometric tailoring.
• Potential applications in 3D spintronic devices, neuromorphic computing, and magnetic memory.