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X-ray-absorption and resonant-photoemission study of Ca in the high-temperature superconductor Bi2Sr2CaCu2O8

Qvarford, M.; Andersen, J. N. LU ; Nyholm, R. LU ; Van Acker, J. F.; Lundgren, E. LU ; Lindau, I. LU ; Söderholm, S.; Bernhoff, H.; Karlsson, U. O. and Flodström, S. A. (1992) In Physical Review B (Condensed Matter) 46(21). p.14126-14133
Abstract

The electronic structure of Ca in the high-temperature superconductor Bi2Sr2CaCu2O8 has been studied by x-ray-absorption spectroscopy and resonant-photoemission at the Ca L2,3 absorption edge. In the x-ray-absorption spectrum no edge structure is seen at the energy corresponding to the Ca 2p3/2 core-level binding energy, in agreement with the very low Ca density of states at the Fermi level predicted by band-structure calculations. Furthermore, the crystal-field splitting of the Ca 3d level, which is characteristic of ionic Ca compounds, is clearly observed in the x-ray-absorption spectrum. The photoemission spectra display strong resonant enhancements of the Ca 3s and 3p core levels as well as strong changes in the intensity and the... (More)

The electronic structure of Ca in the high-temperature superconductor Bi2Sr2CaCu2O8 has been studied by x-ray-absorption spectroscopy and resonant-photoemission at the Ca L2,3 absorption edge. In the x-ray-absorption spectrum no edge structure is seen at the energy corresponding to the Ca 2p3/2 core-level binding energy, in agreement with the very low Ca density of states at the Fermi level predicted by band-structure calculations. Furthermore, the crystal-field splitting of the Ca 3d level, which is characteristic of ionic Ca compounds, is clearly observed in the x-ray-absorption spectrum. The photoemission spectra display strong resonant enhancements of the Ca 3s and 3p core levels as well as strong changes in the intensity and the line shape of the Ca L2,3M2,3M2,3 Auger structure at the Ca L2,3 threshold, showing the localized nature of the 3d states in core ionized Ca. The 3d induced spectator shift of the Ca L2,3M2,3M2,3 complex is fairly small as compared to what has been reported for CaF2, indicating that the screening of the normal Auger final state by the charge carriers in the surrounding Cu-O2 layers is quite efficient. From the Ca L2,3M2,3M2,3 data it is also suggested that, at the Ca L2 threshold, the excited 3d electron participates in a Coster-Kronig-type decay resulting in a 2p3/2 core hole followed by a normal L3M2,3M2,3 Auger decay. © 1992 The American Physical Society.

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organization
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type
Contribution to journal
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published
in
Physical Review B (Condensed Matter)
volume
46
issue
21
pages
8 pages
publisher
American Physical Society
external identifiers
  • Scopus:0009927414
ISSN
0163-1829
DOI
10.1103/PhysRevB.46.14126
language
English
LU publication?
yes
id
2f5d6f3e-e6a6-47d4-a63c-25c78b4b9590
date added to LUP
2016-05-17 14:15:56
date last changed
2016-11-02 15:14:34
@misc{2f5d6f3e-e6a6-47d4-a63c-25c78b4b9590,
  abstract     = {<p>The electronic structure of Ca in the high-temperature superconductor Bi2Sr2CaCu2O8 has been studied by x-ray-absorption spectroscopy and resonant-photoemission at the Ca L2,3 absorption edge. In the x-ray-absorption spectrum no edge structure is seen at the energy corresponding to the Ca 2p3/2 core-level binding energy, in agreement with the very low Ca density of states at the Fermi level predicted by band-structure calculations. Furthermore, the crystal-field splitting of the Ca 3d level, which is characteristic of ionic Ca compounds, is clearly observed in the x-ray-absorption spectrum. The photoemission spectra display strong resonant enhancements of the Ca 3s and 3p core levels as well as strong changes in the intensity and the line shape of the Ca L2,3M2,3M2,3 Auger structure at the Ca L2,3 threshold, showing the localized nature of the 3d states in core ionized Ca. The 3d induced spectator shift of the Ca L2,3M2,3M2,3 complex is fairly small as compared to what has been reported for CaF2, indicating that the screening of the normal Auger final state by the charge carriers in the surrounding Cu-O2 layers is quite efficient. From the Ca L2,3M2,3M2,3 data it is also suggested that, at the Ca L2 threshold, the excited 3d electron participates in a Coster-Kronig-type decay resulting in a 2p3/2 core hole followed by a normal L3M2,3M2,3 Auger decay. © 1992 The American Physical Society.</p>},
  author       = {Qvarford, M. and Andersen, J. N. and Nyholm, R. and Van Acker, J. F. and Lundgren, E. and Lindau, I. and Söderholm, S. and Bernhoff, H. and Karlsson, U. O. and Flodström, S. A.},
  issn         = {0163-1829},
  language     = {eng},
  number       = {21},
  pages        = {14126--14133},
  publisher    = {ARRAY(0x98d3190)},
  series       = {Physical Review B (Condensed Matter)},
  title        = {X-ray-absorption and resonant-photoemission study of Ca in the high-temperature superconductor Bi2Sr2CaCu2O8},
  url          = {http://dx.doi.org/10.1103/PhysRevB.46.14126},
  volume       = {46},
  year         = {1992},
}