X-ray absorption spectroscopy of detwinned Pr{sub x}Y{sub 1{minus}x}Ba{sub 2}Cu{sub 3}O{sub 7{minus}y} single crystals: Electronic structure and hole distribution

Journal Article · Tue Apr 01 04:00:00 EST 1997 · Physical Review, B: Condensed Matter

DOI:https://doi.org/10.1103/PhysRevB.55.9160· OSTI ID:541954

Merz, M; Nuecker, N; Pellegrin, E; Schweiss, P; Schuppler, S ^[1]; Kielwein, M; Knupfer, M; Golden, M S; Fink, J ^[2]; Chen, C T ^[3]; Chakarian, V; Idzerda, Y U ^[4]; Erb, A ^[5]

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1. Forschungszentrum Karlsruhe, INFP, P.O. Box 3640, D-76021 Karlsruhe (Germany)
2. Institut fuer Festkoerper- und Werkstofforschung Dresden, P.O. Box 270016, D-01171 Dresden (Germany)
3. Synchrotron Radiation Research Center, Hsinchu Science-based Industrial Park, Hsinchu 300 (Taiwan)
4. Naval Research Laboratory, Code 6345, Washington, D.C. 20375 (United States)
5. Departement de Physique de la Matiere Condensee, Universite de Geneve, 24, quai Ernest-Ansermet, CH-1211 Geneve (Switzerland)

Substituting Y in orthorhombic (Y,R)Ba{sub 2}Cu{sub 3}O{sub 7} by any rare-earth element R has generally little effect on the superconducting properties. For R=Pr, however, superconductivity is completely suppressed. To understand this effect we have studied the unoccupied electronic structure of Pr{sub x}Y{sub 1{minus}x}Ba{sub 2}Cu{sub 3}O{sub 7{minus}y} (x=0.0, 0.4, 0.8) using polarization-dependent O 1s near-edge x-ray absorption spectroscopy of detwinned single crystals. We identify the hole states in the CuO{sub 2} planes and the CuO{sub 3} chains and give estimates of the relative contributions of the O 2p{sub x}, O 2p{sub y}, and O 2p{sub z} orbitals to these states. Along with the comparison of oxygen-rich (y{approx}0.1) to the oxygen-depleted materials (y{approx}0.9), this allows a test of the current theoretical explanations for the Pr-induced suppression of superconductivity. While we can rule out models involving hole filling or charge transfer between the planes and the chains, our data are consistent with approaches based on Pr 4f{endash}O 2p{sub {pi}} hybridization. {copyright} {ital 1997} {ital The American Physical Society}

• OSTI ID: 541954
• Journal Information: Physical Review, B: Condensed Matter, Journal Name: Physical Review, B: Condensed Matter Journal Issue: 14 Vol. 55; ISSN PRBMDO; ISSN 0163-1829
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
66 PHYSICS
ABSORPTION SPECTRA
BARIUM OXIDES
CHEMICAL COMPOSITION
COPPER OXIDES
CRYSTAL DEFECTS
ELECTRONIC STRUCTURE
HIGH-TC SUPERCONDUCTORS
PRASEODYMIUM OXIDES
TRANSITION TEMPERATURE
TWINNING
X-RAY SPECTROSCOPY
YTTRIUM OXIDES