  The orbital and spin magnetic moments, and the X-ray-magnetic
circular-dichroism (XMCD) spectra at the $M_{4,5}$ edges of the U atoms in a
UAs/Co multilayer and in an $\alpha$-U film are calculated within the framework
of the density-functional theory in combination with the local-spin-density
approximation (LSDA), the generalized-gradient approximation (GGA) and the
LDA+$U$ method. The antiparallel arrangement between the U and Co spin magnetic
moments at the interface results in the vanishing of ferromagnetism for the
case of very thin Co layers. The U moments decay rapidly with the distance from
the film surface. The magnitude of the magnetic-dipole term $<T_z>$, which
appears in the spin XMCD sum rule, is small. The different exchange-correlation
treatments do not yield qualitatively different results.
