The electronic and magnetic structures of a Co11Au4 multi-layer, as well as the corresponding Au L2,3-edge X-ray magnetic dichroism spectra, were calculated for various degrees of interdiffusion at the Co/Au interface. The experimental Au L2,3-edge X-ray magnetic dichroism signal could not be reproduced unless considerable interdiffusion at the Co/Au interface was assumed. Interdiffusion enhanced the induced magnetism of Au, and the magnitudes of spin and orbital magnetic moments of Au increased linearly with the number of Co neighbours. For Co, there was competition between lattice dilatation, which enhanced magnetism, and having Au as a neighbour, which suppressed the magnetism of Co atoms. Low-symmetry and inhomogeneity of the interface region caused the magnetic-dipole term and the number of holes in the d-band to have a significant influence upon quantities related to the X-ray magnetic dichroism sum rules.

Influence of Interdiffusion on the Magnetic Moments in Co/Au Multilayers. O.Šipr, J.Minár, J.Vackář, H.Ebert: Physical Review B, 2007, 75[13], 134422 (10pp)

Figure 1

Diffusivity of H in Co2Tb with Mischmetall Additions

[a: Co2(Tb0.9Mm0.1), b: Co2(Tb0.8Mm0.2), c: Co2Tb]