Photoemission study of Al adlayers on Mn

Abstract

Al overlayers on Mn, studied by photoemission spectroscopy, show a large lowering of the Al 2p core-level binding energy by 0.5 eV at submonolayer (0.1 ML) coverage. The binding energy increases with coverage and reaches the bulk Al value at ≈1.3 ML. The Al 2p core-level spectrum exhibits extra components related to the different chemical environment at the interface, which decrease in intensity with increasing Al coverage. The Al related plasmon loss features appear above 1 ML. The present results are explained by a strong Al s, p-Mn 3d hybridization at the submonolayer coverage due to interface alloying, whose influence on the spectra is dominated by metallic bonding in the Al layer as coverage increases. The valence-band spectra demonstrate systematic suppression of Mn 3d-like states and emergence of a parabolic free-electron-like Al density of states.