- Author
-
S. de Jong
Y. Huang
R. Huisman
F. Massee
R. Thirupathaiah
M. Gorgoi
F. Schaefers
F. Follath
J.B. Goedkoop
M.S. Golden - Year
- 2009
- Title
- High-resolution, hard x-ray photoemission investigation of BaFe2As2: Moderate influence of the surface and evidence for a low degree of Fe 3d-As 4p hybridization of electronic states near the Fermi energy
- Journal
- Physical Review B
- Volume | Issue number
- 79 | 11
- Pages (from-to)
- 115125
- Number of pages
- 8
- Document type
- Article
- Faculty
- Faculty of Science (FNWI)
- Institute
- Van der Waals-Zeeman Institute (WZI)
- Abstract
-
Photoemission data taken with hard x-ray radiation on cleaved single crystals of the barium parent compound of the MFe2As2 pnictide high-temperature superconductor family are presented. Making use of the increased bulk sensitivity upon hard x-ray excitation, and comparing the results to data taken at conventional vacuum ultraviolet photoemission excitation energies, it is shown that the BaFe2As2 cleavage surface provides an electrostatic environment that is slightly different to the bulk, most likely in the form of a modified Madelung potential. However, as the data argue against a different surface doping level, and the surface-related features in the spectra are by no means as dominating as seen in systems such as YBa2Cu3Ox, we can conclude that the itinerant, near-EF electronic states are almost unaffected by the existence of the cleavage surface. Furthermore, exploiting the strong changes in photoionization cross section between the Fe and As states across the wide photon energy range employed, it is shown that the degree of energetic overlap between the iron 3d and arsenic 4p valence bands is particularly small at the Fermi level, which can only mean a very low degree of hybridization between the Fe 3d and As 4p states near and at EF. Consequently, this means that the itinerancy of the charge carriers in this group of materials involves mainly the Fe 3d-Fe 3d overlap integrals with at best a minor role for the Fe 3d-As 4p hopping parameters and that the states which support superconductivity upon doping are essentially of Fe 3d character.
- URL
- go to publisher's site
- Language
- Undefined/Unknown
- Persistent Identifier
- https://hdl.handle.net/11245/1.318171
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