Scaling theory of magneto-resistance in disordered local moment ferromagnets

We present a scaling theory of magneto-transport in Anderson-localized disordered ferromagnets. Within our framework a pronounced magnetic-field-sensitive resistance peak emerges naturally for temperatures near the magnetic phase transition. We find that the resistance anomaly is a direct consequence of the change in localization length caused by the magnetic transition. For increasing values of the external magnetic field, the resistance peak is gradually depleted and pushed towards higher temperatures. Our results are in good agreement with magneto-resistance measurements on a variety of disordered magnets.