Unlocking perpendicular magnetic anisotropy with Gd substitution in SmN

A unique bulk-origin perpendicular magnetic anisotropy (PMA) is reported in thin films of the cubic ferromagnetic semiconductor GdxSm1-xN. PMA behavior is clearly signaled by in-vs-out-of-plane magnetic hysteresis showing out-of-plane remanence of ∼ 80% of the saturation magnetization in films with up to 30% Gd. Anomalous Hall effect data show further that the conduction-band spin imbalance shows complete 100% remanence to retain half-metallic conduction even as the out-of-plane applied field is reduced to zero, in stark contrast to the 80% magnetization remanence. The unusual occurrence of PMA in this cubic material is discussed as stabilized by a mix of two in-plane crystal orientations in the epitaxial (111)-oriented films.