X-ray-absorption and resonant-photoemission study of Ca in the high-temperature superconductor Bi2Sr2CaCu2O8
M. Qvarford, J. N. Andersen, R. Nyholm, J. F. van Acker, E. Lundgren, I. Lindau, S. Söderholm, H. Bernhoff, U. O. Karlsson, S. A. Flodström
DOI 10.1103/PhysRevB.46.14126 · Physical Review B
Active bibliographic source — not scientific approval
Bibliographic access preserves source history; it does not approve extracted materials or validate reported claims. Review warnings on each occurrence separately.
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 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.
Source-reported materials — not catalogue approval
| Formula | Reported Tc (K) | Pressure (GPa) | Type |
|---|---|---|---|
| Bi2Sr2CaCu2O8 Archive — visibility unverified Source-occurrence policy only; no material identity or catalogue acceptance is inferred from the formula. | 90 | Pressure not reported | unknown |
Similar papers
Suppressed superconductivity of the surface conduction layer in Bi2Sr2CaCu2O8+x single crystals probed by c-axis tunneling measurements
similarity 0.95Nam Kim et al.
Source status unknown — claims are unverified
Energy density driven ultrafast electronic excitations in a cuprate superconductor
similarity 0.95Alessandra Milloch et al.
Source status unknown — claims are unverified
Superconducting properties of strongly underdoped Bi2Sr2CaCu2O8+x single crystals
similarity 0.95M. Li et al.
Source status unknown — claims are unverified
Resonant electronic Raman scattering in high-Tc superconductors
similarity 0.95E. Ya. Sherman et al.
Source status unknown — claims are unverified
Features of the density of states of high-Tc superconductors probed by vacuum tunneling
similarity 0.95Jin-Xiang Liu et al.
Source status unknown — claims are unverified
Interlayer tunneling spectroscopy of Bi2Sr2CaCu2O8+δ: A look from inside on the doping phase diagram of high-Tc superconductors
similarity 0.95V. M. Krasnov
Source status unknown — claims are unverified