Influence of Yb on Valence Band Density of States of CdYbTe and PbYbTe - a Resonant Photoemission Study

Photoemission measurements using synchrotron radiation were performed on PbYbTe (bulk crystal) and CdYbTe (MBE thin film). The resonant enhancement of the photoemission was applied for investigation of the contribution of Yb 4f electrons to the valence band. The set of the energy distribution curves was collected for energies in the region close to the 4d-4f Fano transition. The Yb 4f$\text{}^{14}$ were observed at the binding energies close to the edge of the valence band while the 4f$\text{}^{13}$ states were revealed deep in the valence band.