Absorption spectroscopy of electronic states near Fermi level; Temperature changes of superconducting YBa sub 2 Cu sub 3 O sub 7 minus. delta. films at T sub c
- Inst. for Low Temperature Physics and Engineering, UkrSSR Academy of Sciences, Kharkov (SU)
This paper reports that the temperature behavior of the absorption spectra of superconducting YBa{sub 2}-Cu{sub 3}-O{sub 7{minus}{delta}} textured films is measured in a 1.5 + 3.0 eV energy region with varying temperatures from 25 to 300 K. The spectra are found to be sensitive to a superconducting transition: the temperature-dependent behavior of absorption at T {gt} T{sub c} undergoes critical changes under the superconducting transition and for T {lt} T{sub c} the spectrum ceases to depend on temperature. The spectra display an exciton maximum in the optical gap E{sub g} = 1.95 eV. The spectrum freezing at T{lt} T{sub c} can be explained assuming that the Fermi level is in temperature resonance with a narrow local level which is responsible for a delta-like singularity in the density of states.
- OSTI ID:
- 5001291
- Journal Information:
- Modern Physics Letters B; (Singapore), Vol. 6:9; ISSN 0217-9849
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
BARIUM COMPOUNDS
ABSORPTION SPECTRA
CUPRATES
YTTRIUM COMPOUNDS
ELECTRONIC STRUCTURE
ENERGY GAP
ENERGY-LEVEL DENSITY
EV RANGE 01-10
FERMI LEVEL
HIGH-TC SUPERCONDUCTORS
RESONANCE
SINGULARITY
SUPERCONDUCTING FILMS
TEMPERATURE DEPENDENCE
TEMPERATURE RANGE 0013-0065 K
TEMPERATURE RANGE 0065-0273 K
TEMPERATURE RANGE 0273-0400 K
TEXTURE
TRANSITION TEMPERATURE
ALKALINE EARTH METAL COMPOUNDS
COPPER COMPOUNDS
ENERGY LEVELS
ENERGY RANGE
EV RANGE
FILMS
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
SPECTRA
SUPERCONDUCTORS
TEMPERATURE RANGE
THERMODYNAMIC PROPERTIES
TRANSITION ELEMENT COMPOUNDS
360204* - Ceramics
Cermets
& Refractories- Physical Properties
360207 - Ceramics
Cermets
& Refractories- Superconducting Properties- (1992-)