Photoemission is used to examine valence electronic structure of Yb deposited on condensed ammonia or xenon films. The deposition of Yb onto solid ammonia produces a Yb phase whose two 4f peaks lie at a higher binding energy than Yb metal and also produces a feature near the Fermi level. The peak near ${\mathit{E}}_{\mathit{f}}$ is not seen when Yb is isolated in xenon. From the appearance of the Yb 4f levels and the existence of a peak near ${\mathit{E}}_{\mathit{f}}$, it is concluded that the Yb is divalent and that (1) the peak near ${\mathit{E}}_{\mathit{f}}$ is a shakedown satellite derived from the 4f states or (2) the peak near ${\mathit{E}}_{\mathit{f}}$ is due to the hybridization of the Yb 4f states with other Yb or ligand states.

• Received 4 November 1994

DOI:https://doi.org/10.1103/PhysRevB.51.5269