Photoemission spectroscopy of bismuth calcium strontium copper oxide ( in the normal and superconducting state.

Hillebrecht F. U., Fraxedas J., Ley L., Trodahl J., Zaanen J.

Max-Planck-Inst. Festkoerperforsch., Stuttgart , D-7000/80, Fed. Rep. Ger.

XPS and UPS valence band spectra of are reported and compared to spectra predicted within the local d. approxn. The Cu d/O p band dominates the spectra at all photon energies, although it is found 1-2 eV lower than predicted. This results from electronic correlations which enhance the anisotropy of the ground state charge distribution. The only change obsd. upon entering the superconducting state is the expected sharpening of the Fermi edge. No evidence was found for the formation of a gap of .gtoreq.15 meV.

High Tc Supercond., Proc. Int. Symp. Electron. Struct. of High Tc Supercond. Editors: Bianconi, A. Marcelli, A. Oxford, UK: Pergamon, 1989. p. 181-4 of x+339 pp. 6 refs. Conference: Rome, Italy, 5-7 Oct 1988 Sponsor(s): Assoc. Amici Accad. Lincei; Europa Metalli-LMI; CNR; ENEA ISBN: 0-08-037542-1.

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