Theory of magnetic domains in uniaxial thin films

TL;DR

This paper introduces a comprehensive model for magnetic domains in uniaxial thin films that accounts for magnetostatic energies and surface interactions, improving understanding of domain behavior and phase transitions.

Contribution

The model incorporates magnetostatic energy and surface interactions, providing a more accurate description of domain and wall widths across film thicknesses, especially in the stripe phase.

Findings

Existence of a critical anisotropy value for stripe domains

Model aligns well with experimental data for hcp cobalt

Predicts domain behavior as a function of film thickness

Abstract

For uniaxial easy axis films, properties of magnetic domains are usually described within the Kittel model, which assumes that domain walls are much thinner than the domains. In this work we present a simple model that includes a proper description of the magnetostatic energy of domains and domain walls and also takes into account the interaction between both surfaces of the film. Our model describes the behavior of domain and wall widths as a function of film thickness, and is especially well suited for the strong stripe phase. We prove the existence of a critical value of magneto-crystalline anisotropy above which stripe domains exist for any film thickness and justify our model by comparison with exact results. The model is in good agreement with experimental data for hcp cobalt.