Field-driven single domain wall motion in ferromagnetic nanowires

Area of Science:

• Materials Science
• Condensed Matter Physics
• Nanotechnology

Background:

• Magnetic domain walls are key to novel data storage concepts like racetrack memory.
• Controlling domain wall motion in nanostructures is essential for device functionality.

Purpose of the Study:

• To design and investigate 2D permalloy nanostructures as single magnetic domain wall traps.
• To determine geometric parameters for reproducible domain wall propagation using external magnetic fields.

Main Methods:

• Lorentz microscopy for observing domain wall behavior.
• Micro-magnetic simulations (OOMMF) for theoretical analysis.
• Electron beam lithography and focused ion beam for nanofabrication.

Main Results:

• A specific trap design with two horizontal nanowires and three 90°-tilted pads allows reproducible domain wall motion with two field directions.
• Domain wall propagation is sensitive to corner geometry and angles of nanostructure elements.
• Domain wall pinning and chirality changes correlate with specific trap geometries.

Conclusions:

• Precise geometric engineering of nanostructures is vital for reliable domain wall manipulation.
• Optimized domain wall traps can advance the development of high-density, nonvolatile magnetic memory and logic devices.