Scaling of Magnetic Domain Walls in Perpendicular Magnetic Anisotropy Systems

Magnetic domain walls play a critical role in the nanoscale evolution of magnetic devices. Despite the early efforts, a complete understanding of the micromagnetic evolution of the width and the type of magnetic domain walls has still remained missing. Here, we report a combined analytical and micromagnetic simulation study and establish the scaling of the magnetic domains as a function of the exchange stiffness (A), uniaxial perpendicular magnetic anisotropy (Ku), saturation magnetization (Ms), and Dzyaloshinskii-Moriya interaction (DMI), and shape anisotropy of the magnetic device. We find that the width of both Bloch and Neel walls scales excellently with the analytical prediction. The DMI is found to have little influence on the domain wall width but strongly affect the type of the domain wall. The domain wall has a Bloch configuration at zero DMI and gradually transitions to Neel configuration upon increase of the DMI. The shape anisotropy of the magnetic domain wall also affects the domain wall width. These results have established a comprehensive, conclusive understanding of the magnetic domain walls within spintronics devices.

💡 Research Summary

The authors present a comprehensive study of magnetic domain walls (DWs) in perpendicular magnetic anisotropy (PMA) thin films, focusing on how the exchange stiffness (A), uniaxial anisotropy (Ku), saturation magnetization (Ms), Dzyaloshinskii‑Moriya interaction (DMI), and shape anisotropy (through the demagnetizing factor Nx) determine both the wall width (Δ) and its internal spin configuration. Starting from a continuous rotation model of the magnetization, they write the total energy density as the sum of exchange, anisotropy, demagnetizing, and DMI contributions. By applying a variational minimization they derive a unified analytical expression for the wall width:

Δ = C · √