Electronic structure studies on the n -type doped superconductors R sub 2 minus x M x CuO sub 4 minus. delta. ( R =Pr,Nd,Sm; M =Ce,Th) and Nd sub 2 CuO sub 4 minus x F sub x by electron-energy-loss spectroscopy

Journal Article · Tue Jan 01 00:00:00 EST 1991 · Physical Review, B: Condensed Matter; (USA)

DOI:https://doi.org/10.1103/PhysRevB.43.333· OSTI ID:6108298

Alexander, M; Romberg, H; Nuecker, N; Adelmann, P; Fink, J ^[1]; Markert, J T; Maple, M B ^[2]; Uchida, S; Takagi, H; Tokura, Y ^[3]; James, A C.W.P.; Murphy, D W ^[4]

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1. Kernforschungszentrum Karlsruhe, Institut fuer Nukleare Festkoerperphysik, P.O. Box 3640, D-7500 Karlsruhe, West Germany (DE)
2. Department of Physics and Institute for Pure and Applied Physical Science, University of California, San Diego, La Jolla, California (USA)
3. University of Tokyo, Bunkyo-ku, Tokyo (Japan)
4. AT T Bell Laboratories, Murray Hill, New Jersey (USA)

The electronic structure of the high-{ital T}{sub {ital c}} superconductors {ital R}{sub 2{minus}{ital x}M{ital x}}CuO{sub 4{minus}{delta}} ({ital R}=Pr, Nd, Sm; {ital M}=Ce, Th) and Nd{sub 2}CuO{sub 3.8}F{sub 0.2} has been studied by high-energy electron-energy-loss spectroscopy in transmission. Core-level spectroscopy, particularly on O 1{ital s} and Cu 2{ital p} levels yields information on the partial unoccupied density of states near the Fermi level, while that on {ital R} and Ce 3{ital d} and 4{ital d} levels may serve as a valence monitor for these constituents. A pre-edge structure in the O 1{ital s} spectrum is polarized in the CuO{sub 2} plane and assigned to transitions into a two-dimensional conduction band consisting of Cu 3{ital d} hybridized to O 2{ital p} states. In the Cu 3{ital d}{sup 9} configuration we found a slight admixture ({similar to}10%) of Cu 3{ital d}{sub 3{ital z}}{sup 2}{minus}{ital r}{sup 2} to the Cu 3{ital d}{sub {ital x}}{sup 2}{minus}{ital y}{sup 2} hole states similar to the {ital p}-type doped superconductors. Upon doping we recognized a reduction ({similar to}14%) of the excitonic Cu 2{ital p}{sub 3/2} line, indicating that the introduced electrons go onto the Cu sites, thus producing charge carriers having predominantly Cu 3{ital d} character.

• DOE Contract Number: FG03-86ER45230
• OSTI ID: 6108298
• Journal Information: Physical Review, B: Condensed Matter; (USA), Vol. 43:1, Issue 1; ISSN 0163-1829
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
CERIUM OXIDES
ELECTRONIC STRUCTURE
COPPER OXIDES
NEODYMIUM OXIDES
PRASEODYMIUM OXIDES
SAMARIUM OXIDES
THORIUM OXIDES
ENERGY-LEVEL DENSITY
ENERGY-LOSS SPECTROSCOPY
FERMI LEVEL
FLUORINE ADDITIONS
HIGH-TC SUPERCONDUCTORS
HYBRIDIZATION
N-TYPE CONDUCTORS
RARE EARTH COMPOUNDS
ACTINIDE COMPOUNDS
CERIUM COMPOUNDS
CHALCOGENIDES
COPPER COMPOUNDS
ELECTRON SPECTROSCOPY
ENERGY LEVELS
MATERIALS
NEODYMIUM COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
PRASEODYMIUM COMPOUNDS
SAMARIUM COMPOUNDS
SEMICONDUCTOR MATERIALS
SPECTROSCOPY
SUPERCONDUCTORS
THORIUM COMPOUNDS
TRANSITION ELEMENT COMPOUNDS
360204* - Ceramics
Cermets
& Refractories- Physical Properties