XMCD characterization of rare-earth dopants in Ni₈₁Fe₁₉(50nm): microscopic basis of engineered damping
Bailey, W. E. · Cheng, L. · Song, H.
Original · EN
We present direct evidence for the contribution of local orbital moments to the damping of magnetization precession in magnetic thin films. Using x-ray magnetic circular dichroism (XMCD) characterization of rare-earth (RE) M₄,₅ edges in Ni₈₁Fe₁₉ doped with < 2% Gd and Tb, we show that the enhancement of GHz precessional relaxation is accompanied by a significant orbital moment fraction on the RE site. Tb impurities, which enhance the Landau-Lifshitz(-Gilbert) LL(-G) damping λ(α), show a spin to orbital number ratio of 1.5±0.3; Gd impurities, which have no effect on damping, show a spin to orbital number ratio of zero within experimental error. The results indicate that the dopant-based control of magnetization damping in RE-doped ferromagnets is an atomistic effect, arising from spin-lattice coupling, and thus scalable to nanometer dimensions.
English translation
This paper has no Arabic translation yet. Be the first: it takes a few seconds, and the result is stored for every future reader.