Dresden 2006 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Downloads | Hilfe
TT: Tiefe Temperaturen
TT 25: Correlated Electrons - Poster Session
TT 25.62: Poster
Mittwoch, 29. März 2006, 14:30–18:30, P1
Bulk and Surface Photoemission in Ytterbium Compounds — •Stefan W. Schmidt1, Friedrich Reinert2, and Stefan Hüfner1 — 1Universität des Saarlandes, 7.2 Experimentalphysik, D-66041 Saarbrücken, Germany — 2Universität Würzburg, Experimentelle Physik II, D-97084 Würzburg, Germany
We have investigated a broad range of intermetallic intermediate-valent Yb compounds with high-resolution UPS. The results lead to interesting correlations between the binding energy ε0 and the linewidth Γ0 of the near-EF spectroscopic structure and the ytterbium valence υYb in these systems, and we discuss the influence of crystal field effects to the interpretation of our data.
From an investigation of the first order valence phase transition observed in the 4f- and 4d-XPS data of the prototypical compound YbInCu4 [1] and a comparison to existing PE data [2, 3], we conclude that a surface-near region of thickness d≈20–40 Å with different physical properties could be common to these materials. Therefore, the theoretical modelling of these systems on the base of UPS data has to consider the systematic differences between bulk and surface sensitive PES measurements, especially in comparison to thermodynamic measurements or bulk sensitive methods.
[1] S. Schmidt, S. Hüfner, F. Reinert and W. Assmus, Phys. Rev. B 72, 195110 (2005).
[2] H. Sato et al., Phys. Rev. Lett. 93, 246404 (2004).
[3] H. Sato et al., Phys. Rev. B 69, 165101 (2004).