Symmetry of holes in high-T/sub c/ superconductors

Journal Article · Fri Mar 31 23:00:00 EST 1989 · Phys. Rev. B: Condens. Matter; (United States)

DOI:https://doi.org/10.1103/PhysRevB.39.6619· OSTI ID:6317397

Nuecker, N; Romberg, H; Xi, X X; Fink, J; Gegenheimer, B; Zhao, Z X

High-energy electron energy-loss spectroscopy in transmission has been used to obtain information on the symmetry of unoccupied electronic states in the new high-T/sub c/ superconductors. In particular, for YBa/sub 2/Cu/sub 3/O/sub 7/ and Bi/sub 2/Sr/sub 2/CaCu/sub 2/O/sub 8/, the O 1s and Cu 2p absorption edges have been measured for momentum transfer parallel and perpendicular to the a,b plane. Both sigma and in-plane ..pi.. holes on O, formed upon doping, are compatible with our experimental results. For YBa/sub 2/Cu/sub 3/O/sub 7/, in both cases, holes must be in the planes and in the ribbons. Out-of-plane ..pi.. holes can be excluded for YBa/sub 2/Cu/sub 3/O/sub 7/ and Bi/sub 2/Sr/sub 2/CaCu/sub 2/O/sub 8/. In the undoped and doped compounds, the unoccupied states on the Cu sites have predominantly in-plane 3d/sub x//sub <2/-y/sup =/ symmetry. There is an admixture of about 10% of lower-lying states probably with 3d/sub 3//sub z//sub <2/-r/sup =/ symmetry.

• Research Organization: Kernforschungszentrum Karlsruhe, Institut fuer Nukleare Festkoerperphysik, Postfach 3640, D-7500 Karlsruhe, Federal Republic of Germany
• OSTI ID: 6317397
• Journal Information: Phys. Rev. B: Condens. Matter; (United States), Journal Name: Phys. Rev. B: Condens. Matter; (United States) Vol. 39:10; ISSN PRBMD
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360204* -- Ceramics
Cermets
&amp; Refractories-- Physical Properties
656100 -- Condensed Matter Physics-- Superconductivity
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ABSORPTION SPECTRA
ALKALINE EARTH METAL COMPOUNDS
BARIUM COMPOUNDS
BARIUM OXIDES
BISMUTH COMPOUNDS
BISMUTH OXIDES
CALCIUM COMPOUNDS
CALCIUM OXIDES
CHALCOGENIDES
COPPER COMPOUNDS
COPPER OXIDES
ELECTRON SPECTROSCOPY
ELECTRONIC STRUCTURE
ELECTRONS
ELEMENTARY PARTICLES
ENERGY-LOSS SPECTROSCOPY
FERMIONS
HOLES
LEPTONS
OXIDES
OXYGEN COMPOUNDS
SPECTRA
SPECTROSCOPY
STRONTIUM COMPOUNDS
STRONTIUM OXIDES
SUPERCONDUCTORS
SYMMETRY
TRANSITION ELEMENT COMPOUNDS
YTTRIUM COMPOUNDS
YTTRIUM OXIDES