Surface magnetic canting in a ferromagnet

TL;DR

This paper investigates surface magnetic canting in ferromagnetic films with competing anisotropies using an extended mean-field theory, analyzing effects of external magnetic fields applied parallel and perpendicular to the film plane.

Contribution

It extends a nonlinear mapping mean-field approach to include external magnetic fields and analyzes surface canting conditions in ferromagnetic films.

Findings

Surface canting condition matches previous reports for in-plane fields.

Perpendicular fields also influence surface canting configurations.

Zero-temperature equilibrium states are determined effectively by the method.

Abstract

The surface magnetic canting (SMC) of a semi-infinite film with ferromagnetic exchange interaction and competing bulk and surface anisotropies is investigated via a nonlinear mapping formulation of mean-field theory previously developed by our group [L. Trallori et al., Int. J. Mod. Phys. B 10, 1935-1988 (1996)], and extended to the case where an external magnetic field is applied to the system. When the field H is parallel to the film plane, the condition for SMC is found to be the same as that recently reported by Popov and Pappas [Phys. Rev. B 64, 184401 (2001)]. The case of a field H applied perpendicularly to the film plane is also investigated. In both cases, the zero-temperature equilibrium configuration is easily determined by our theoretical approach.