Surface and interface magnetism in Fe overlayers on Cr(001)

The surface and the interface magnetism in Fe overlayers on Cr(001) is investigated using the full-potential linearized augmented plane wave band method. In order to examine overlayer effects systematically, one-monolayer Fe (1Fe/Cr(001)) and two-monolayer Fe (2Fe/Cr(001)) on Cr(001) are considered. The results for the spin densities, the magnetic moments, and the density of states are presented. It is found that (i) the magnetic moment at the surface Fe in 1Fe/Cr(001) is 2.44 mu(B), which is smaller than that of the surface Fe in 2Fe/Cr(001) (2.84 mu(B)) and that of a clean bcc Fe surface (2.98 mu(B)), (ii) the magnetic moment of the interface Fe in 2Fe/Cr(001) is reduced to 1.88 mu(B), and (iii) the magnetic moments of the inner Cr layers in 2Fe/Cr(001) are found to be small (< 0.30 mu(B)) while the magnetic moments of the inner Cr layers in 1Fe/Cr(001) are slightly enhanced (similar to 0.70 mu(B)) compared with the bulk value (0.59 mu(B)). These features are due to a strong hybridization between the Fe-d and the Cr-d states, which is verified by the layer-projected density of states.