Photoemission studies of high-temperature superconductors YBa/sub 2/Cu/sub 3/O/sub 7/. sqrt. /sub delta/, GdBa/sub 2/Cu/sub 3/O/sub 7/. sqrt. /sub delta/, and EuBa/sub 2/Cu/sub 3/O/sub 7/. sqrt. /sub delta/

Journal Article · Fri Apr 01 04:00:00 EST 1988 · Phys. Rev. B: Condens. Matter; (United States)

DOI:https://doi.org/10.1103/PhysRevB.37.5164· OSTI ID:5311136

Samsavar, A; Miller, T; Chiang, T; Pazol, B G; Friedmann, T A; Ginsberg, D M

The electronic structures of three high-temperature superconducting materials, YBa/sub 2/Cu/sub 3/O/sub 7/..sqrt../sub delta/, GdBa/sub 2/Cu/sub 3/O/sub 7/..sqrt../sub delta/, and EuBa/sub 2/Cu/sub 3/O/sub 7/..sqrt../sub delta/, were studied with angle-integrated photoemission. The effects of sample treatment and preparation, including mechanical scraping, ion sputtering, and temperature cycling, were examined. High-resolution spectra were obtained from samples prepared by mechanical scraping at 90 K in the vacuum chamber to minimize contamination and the loss of oxygen. The resonance behavior of the various valence and core states in the photoemission spectra was investigated to identify the atomic origin of the states. The Cu- and O-derived states dominated the valence-band region at low photon energies, as shown by a comparison of the energy distribution curves for all three compounds. The measured density of states at the Fermi edge was very low. All of the spectral features, including the valence bands, core levels, Fermi-edge emission, and the Cu 3d satellites did not show any noticeable changes as a function of sample temperature between 20 and 300 K

• Research Organization: Department of Physics and Materials Research Laboratory, University of Illinois at Urbana-Champaign, 1110 West Green Street, Urbana, Illinois 61801
• OSTI ID: 5311136
• Journal Information: Phys. Rev. B: Condens. Matter; (United States), Journal Name: Phys. Rev. B: Condens. Matter; (United States) Vol. 37:10; ISSN PRBMD
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360204* -- Ceramics
Cermets
& Refractories-- Physical Properties
656100 -- Condensed Matter Physics-- Superconductivity
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ALKALINE EARTH METAL COMPOUNDS
BARIUM COMPOUNDS
BARIUM OXIDES
BREMSSTRAHLUNG
CHALCOGENIDES
COPPER COMPOUNDS
COPPER OXIDES
ELECTROMAGNETIC RADIATION
ELECTRON SPECTROSCOPY
ELECTRONIC EQUIPMENT
ELECTRONIC STRUCTURE
ELEMENTS
ENERGY LEVELS
ENERGY-LEVEL DENSITY
EQUIPMENT
EUROPIUM
FERMI LEVEL
FLUXMETERS
GADOLINIUM COMPOUNDS
GADOLINIUM OXIDES
LOW TEMPERATURE
MAGNETOMETERS
MEASURING INSTRUMENTS
MEDIUM TEMPERATURE
METALS
MICROWAVE EQUIPMENT
OXIDES
OXYGEN COMPOUNDS
PHOTOELECTRON SPECTROSCOPY
RADIATIONS
RARE EARTH COMPOUNDS
RARE EARTHS
SPECTROSCOPY
SPUTTERING
SQUID DEVICES
SUPERCONDUCTING DEVICES
SUPERCONDUCTORS
SYNCHROTRON RADIATION
TRANSITION ELEMENT COMPOUNDS
ULTRAHIGH VACUUM
VERY LOW TEMPERATURE
YTTRIUM COMPOUNDS
YTTRIUM OXIDES