Chemisorption-induced changes in surface magnetism and electronic structure: Oxygen on Ni(110)

The effect of oxygen chemisorption on the Ni minority-spin 3d holes---and thus the Ni magnetic moment---is measured by spin-polarized inverse photoemission. A dramatic reduction of the minority-spin 3d holes is observed, indicating a strong involvement of these states in the chemisorptive bond. This reduction can be explained by a Ni 3d--O 2p interaction which redistributes the density of states; no indication of a reduced exchange splitting is found. Majority-spin sp states are shown to be unchanged at coverages below the onset of nucleation and oxide formation.