Orbital magnetism and magnetic anisotropy probed with ferromagnetic resonance

Via ferromagnetic resonance both the magnetic anisotropy energy (MAE) and t he spectroscopic splitting tensor (g tensor) for a bcc Fe-2/V-5(001) superl attice are measured independently. The theoretically proposed proportionali ty between the anisotropy of the orbital moment mu(L) and the MAE is quanti tatively checked and its limitations are discussed. From layer-resolved fir st-principles calculations we find a reduced spin moment mu(S) = 1.62 mu(B) for Fe and mu(S)(V) = -0.67 mu(B) in the first V layer. The g-tensor eleme nts reveal a 300% enhanced ratio mu(L)/mu(S) = 0.133 in comparison to bulk Fe. The MAE and the orbital moment anisotropy is found to be unusually smal l for Fe monolayers.