We investigate the harmonic magnon modes in a model ferromagnet with random-axis anisotropy. Using a numerical approach, we calculate the density of states and characterize the localization of the eigenfunctions. It is shown that, when the anisotropy is large, applying a saturating field greatly enhances the effects of the disorder introduced by the anisotropy.

• Received 17 November 1988

DOI:https://doi.org/10.1103/PhysRevB.39.4453