Magnetic circular x-ray dichroism of submonolayer Mn on Fe(100)

The magnetic behavior of monolayer and submonolayer quantities of Mn adsorbed on an Fe(100) surface is studied using the element-specific magnetic circular x-ray dichroism (MCXD) method in absorption. The shape of the Mn-MCXD spectrum for 0.02 monolayer coverage agrees well with a recent calculation for high-spin Mn if experimental broadening is taken into account. Also the size of the MCXD effect indicates a large net magnetic moment, with the asymmetry at the $L_3$ edge reaching 80% of the value predicted by the theoretical spectrum for the atomic $d^5$ configuration. The sign of the Mn moment is antiparallel to the Fe substrate. With increasing coverage the net Mn magnetic moment rapidly decreases and vanishes for a complete monolayer Mn/Fe(100).