Increased intrinsic anomalous Hall effect from rare earth content in amorphous SmxCo1−x films

Abstract

The low temperature anomalous Hall effect in amorphous sputtered SmxCo1−x films is investigated. The microstructure and amorphous nature of the films were characterized by local area diffraction through transmission electron microscopy. The Sm/Co ratio was changed to elucidate the origin of the anomalous Hall effect, which is a proxy for spin polarized transport. The anomalous Hall effect obeys a scaling relation that points to an intrinsic Berry-curvature based mechanism, consistent with recent reports on other amorphous magnetic materials. The anomalous Hall angle increases with increasing Sm content and reaches large values of ∼1%. This observation is related to recent measurements of the local structure in amorphous Sm–Co alloys and suggests that rare earth elements can be utilized to improve electrical control over spin polarization in amorphous magnetic films.