Variations in the lifetime of 3d hole states in ultrathin Fe films grown on Cu(100) deduced from the LMM Auger spectra of Fe

The Fe LMM Auger and Auger vacancy satellite spectra of ultrathin Fe lms grown on Cu(100)have been measured using photon excitation energies above and below the L2 ionisation edge, and incoincidence with the Fe 2p3=2 and Fe 2p1=2 photoelectrons. A comparison of the relative intensities ofthe satellites and main Auger transitions indicates that the M4;5 holes of L3M4;5 double hole states arelocalised for longer than the L3 lifetime for the 0.3 and 10 ML coverages but have a lifetime comparableto that of L3 holes for the 1 ML coverage. The results for the 1 ML coverage are supported by theresults of the coincidence experiments. The reasons for the variation in the lifetime of M4;5 holes arediscussed in terms of changes in the number of Fe{Fe neighbours and the density of states at the Fermienergy in these systems.