Electronic structure of LaFeAsO1-xFx from x-ray absorption spectroscopy
Publication date
2008-12
Authors
Kroll, T.
Bonhommeau, S.
Kachel, T.
Duerr, H. A.
Werner, J.
Behr, G.
Koitzsch, A.
Huebel, R.
Leger, S.
Schoenfelder, R.
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Advisors
Supervisors
Document Type
Article
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Abstract
We investigated the recently found superconductor LaFeAsO1-xFx by x-ray absorption spectroscopy. From a comparison of the O K edge with LDA calculations we find good agreement and are able to explain the structure and changes in the spectra with electron doping. From experimental Fe L-2,L-3-edge spectra and charge-transfer multiplet calculations we gain further information on important physical values such as the hopping parameters, the charge-transfer energy Delta, and the Hubbard U. Furthermore we find the system to be very covalent with a large amount of ligand holes. A shift in the chemical potential is visible in the O K- and Fe L-2,L-3-edge spectra which emphasizes the importance of band effects in these compounds. From the entirety of our results we conclude that LaFeAsO is a bandwidth-dominated material.
Keywords
charge exchange, chemical potential, Fermi level, high-temperature superconductors, Hubbard model, iron compounds, lanthanum compounds, superconducting materials, X-ray absorption spectra, LAYERED SUPERCONDUCTOR LAO0.9F0.1-DELTA-FEAS, 43 K, COMPOUND, GAP
Citation
Kroll, T, Bonhommeau, S, Kachel, T, Duerr, H A, Werner, J, Behr, G, Koitzsch, A, Huebel, R, Leger, S, Schoenfelder, R, Ariffin, A K, Manzke, R, de Groot, F M F, Fink, J, Eschrig, H, Buechner, B & Knupfer, M 2008, 'Electronic structure of LaFeAsO1-xFx from x-ray absorption spectroscopy', Physical Review B - Condensed Matter and Materials Physics, vol. 78, no. 22, 220502. https://doi.org/10.1103/PhysRevB.78.220502