ANGLE-RESOLVED PHOTOEMISSION-STUDY OF OXYGEN-CHEMISORPTION ON GD(0001)

The initial stages of oxidation and the electronic structure of chemisorbed oxygen on Gd(0001) thin films have been studied by angle-resolved photoelectron spectroscopy. Dissociative chemisorption of oxygen occurs with initial exposures and is followed by formation of a more complex surface oxide of Gd. The symmetry of oxygen-induced states has been identified. Initial oxygen chemisorption occurs through bonding to the Gd(0001) surface via the p(x,y) derived oxygen states. The surface work function decreases with initial oxygen adsorption. The electronic structure induced by oxygen and the work function change indicate that the chemisorbed oxygen layer is below the plane of the Gd(0001) surface layer.