Soft-x-ray-absorption studies of Tl sub 2 Ba sub 2 Ca sub 2 Cu sub 3 O sub 10 minus. delta. high- T sub c superconductors
- Department of Physics and New York State Institute on Superconductivity, State University of New York at Buffalo, Buffalo, New York 14260 (United States)
- Department of Chemistry, State University of New York at Buffalo, Buffalo, New York 14260 (United States)
- Brookhaven National Laboratory, Upton, New York 11973 (United States)
X-ray absorption around the oxygen {ital K} and the Cu {ital L}{sub III} edge of Tl{sub 2}Ba{sub 2}Ca{sub 2}Cu{sub 3}O{sub 10{minus}{delta}} high-{ital T}{sub {ital c}} superconductors with different oxygen content {delta}, was measured. Near the O 1{ital s} edge, three distinct pre-edge peaks with maxima at 528.3, 529.4, and 530.6 eV, respectively, are revealed. They are ascribed to core-level excitations of oxygen 1{ital s} electrons to empty states which have predominantly oxygen 2{ital p} character, located in CuO{sub 2}, BaO, and TlO planes, respectively. A strong dependence of {ital T}{sub {ital c}} on oxygen hole concentration at O(1) and O(1){prime} sites in the CuO{sub 2} layer is found. Near the Cu 2{ital p}{sub 3/2} edge, two main peaks are observed. The peak at 931.2 eV is ascribed to a 2{ital p}3{ital d}{sup 10} final state. This implies a predominately Cu{sup 2+} ground state which has mainly 3{ital d}{sup 9} character. The peak at 933 eV is ascribed to a 2{ital p}3{ital d}{sup 10}{ital L} final state. This peak shows an intensity increase with {ital T}{sub {ital c}}, i.e., with ligand hole concentration, and is believed to arise from a formally Cu{sup 3+} ground state which has mainly 3{ital d}{sup 9}{ital L} character. No evidence of a monovalent (Cu{sup 1+}) 3{ital d}{sup 10} ground state was found.
- DOE Contract Number:
- FG02-87ER45283; AC02-76CH00016
- OSTI ID:
- 7048176
- Journal Information:
- Physical Review, B: Condensed Matter; (United States), Journal Name: Physical Review, B: Condensed Matter; (United States) Vol. 45:17; ISSN 0163-1829; ISSN PRBMD
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
360204* -- Ceramics
Cermets
& Refractories-- Physical Properties
360207 -- Ceramics
Cermets
& Refractories-- Superconducting Properties-- (1992-)
ABSORPTION SPECTRA
ALKALINE EARTH METAL COMPOUNDS
BARIUM COMPOUNDS
BARIUM OXIDES
CALCIUM COMPOUNDS
CALCIUM OXIDES
CHALCOGENIDES
COPPER COMPOUNDS
COPPER OXIDES
ELECTROMAGNETIC RADIATION
ELECTRONIC STRUCTURE
ENERGY LEVELS
GROUND STATES
HIGH-TC SUPERCONDUCTORS
IONIZING RADIATIONS
LIGANDS
OXIDES
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
RADIATIONS
SOFT X RADIATION
SPECTRA
SUPERCONDUCTORS
THALLIUM COMPOUNDS
THALLIUM OXIDES
THERMODYNAMIC PROPERTIES
TRANSITION ELEMENT COMPOUNDS
TRANSITION TEMPERATURE
X RADIATION