The interaction of Li and oxygen has been studied at 25 K. This system serves as an excellent prototype for studying the interaction of alkali metals with oxygen. For some of the alkali metals, such as Cs or K, oxygen can be incorporated below the metal surface and complex valence-band and core-level features are obtained. In the case of Li at 25 K this does not appear to happen, and the core-level and valence-band features can be identified with the formation of the superoxide, the peroxide, and the oxide.

• Received 5 October 1988

DOI:https://doi.org/10.1103/PhysRevB.39.6194