Magnetic Reversal on Vicinal Surfaces

TL;DR

This paper provides a theoretical analysis of in-plane magnetization reversal in vicinal ultrathin films, highlighting how step anisotropy and terrace length influence reversal mechanisms and hysteresis loop shapes.

Contribution

It introduces a detailed phase diagram for reversal mechanisms in vicinal films using a one-dimensional micromagnetic model, emphasizing the role of steps in nucleation and domain wall pinning.

Findings

Steps nucleate magnetization reversal

Step anisotropy influences reversal mechanisms

No sharp transition between reversal modes

Abstract

We present a theoretical study of in-plane magnetization reversal for vicinal ultrathin films using a one-dimensional micromagnetic model with nearest-neighbor exchange, four-fold anisotropy at all sites, and two-fold anisotropy at step edges. A detailed "phase diagram" is presented that catalogs the possible shapes of hysteresis loops and reversal mechanisms as a function of step anisotropy strength and vicinal terrace length. The steps generically nucleate magnetization reversal and pin the motion of domain walls. No sharp transition separates the cases of reversal by coherent rotation and reversal by depinning of a ninety degree domain wall from the steps. Comparison to experiment is made when appropriate.