We study Anderson localization of spin waves in Heisenberg ferromagnets with weak randomaxes anisotropy and large net magnetization, induced by the external magnetic field. Two regimes, depending on the strength of the field, are distinguished: (1) in smaller fields, the regime with the field-dependent correlations of the transverse component of the magnetization—the ferromagnet with wandering axis; (2) in larger fields, the mean-field regime with the transverse magnetization uncorrelated from site to site. In both cases, we find the mobility edge and show that it can be tuned by the magnetic field.

• Received 3 March 1988

DOI:https://doi.org/10.1103/PhysRevB.37.9901