Experimental electronic structure of Bi/sub 2/CaSr/sub 2/Cu/sub 2/O/sub 8+//sub delta/

Journal Article · Sat Dec 31 23:00:00 EST 1988 · Phys. Rev. B: Condens. Matter; (United States)

DOI:https://doi.org/10.1103/PhysRevB.39.236· OSTI ID:6481334

Hillebrecht, F U; Fraxedas, J; Ley, L; Trodahl, H J; Zaanen, J; Braun, W; Mast, M; Petersen, H; Schaible, M; Bourne, L C; others, and

Highly oriented polycrystalline Bi/sub 2/CaSr/sub 2/Cu/sub 2/O/sub 8+//sub delta/ has been studied by x-ray photoemission spectroscopy (XPS) to determine the oxidation states of its constituents and the valence electronic structure. Core-level shifts indicate 3/sup +/ and 2/sup +/ as main oxidation states for Bi and Cu, respectively. The Ca and Sr core levels exhibit pronounced shifts to lower binding energy compared to the metals. The Ca lines show two main components, indicating either inequivalent sites or the presence of a different phase. The XPS and ultraviolet photoemission spectroscopy valence-band spectra show weak but reproducible metallic emission at the Fermi level (E/sub F/) which we ascribe to states originating in the Bi-O planes. The main Cu d--O p band is between 2 and 8 eV below E/sub F/; this is about 1 eV lower than predicted by band-structure calculations. We argue that this is due to electronic correlations tending to increase the anisotropy in the ground-state charge distribution compared to that obtained in local-density-approximation calculations.

• Research Organization: Max-Planck-Institut fuer Festkoerperforschung, Heisenbergstrasse 1, D-7000 Stuttgart 80, Federal Republic of Germany
• OSTI ID: 6481334
• Journal Information: Phys. Rev. B: Condens. Matter; (United States), Journal Name: Phys. Rev. B: Condens. Matter; (United States) Vol. 39:1; ISSN PRBMD
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360204* -- Ceramics
Cermets
& Refractories-- Physical Properties
ALKALINE EARTH METAL COMPOUNDS
ANISOTROPY
BINDING ENERGY
BISMUTH COMPOUNDS
BISMUTH OXIDES
CALCIUM COMPOUNDS
CALCIUM OXIDES
CHALCOGENIDES
CHARGE DENSITY
CHEMICAL REACTIONS
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ELECTRON SPECTROSCOPY
ELECTRONIC STRUCTURE
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GROUND STATES
IONIZING RADIATIONS
ORIENTATION
OXIDATION
OXIDES
OXYGEN COMPOUNDS
PHOTOELECTRON SPECTROSCOPY
POLYCRYSTALS
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SUPERCONDUCTORS
TRANSITION ELEMENT COMPOUNDS
ULTRAVIOLET RADIATION
X RADIATION