Cu(1) and Cu(2) NMR in YBa sub 2 Cu sub 3 O sub 7

Journal Article · Fri Jun 01 04:00:00 EDT 1990 · Physical Review, B: Condensed Matter; (USA)

DOI:https://doi.org/10.1103/PhysRevB.41.11128· OSTI ID:6974401

Monthoux, P ^[1]

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1. Department of Physics, University of Illinois at Urbana-Champaign, 1110 West Green Street, Urbana, Illinois 61801 (US)

Cu(1) and Cu(2) spin-lattice relaxation times and Knight-shift tensors in the normal state have been calculated using simple tight-binding models of the band structure. A picture with copper {ital d} bands totally fails to reproduce the observed relaxation rates and Knight shifts. The obtained Cu(1) and Cu(2) {ital T}{sub 1}'s are off by several orders of magnitude. The spin contributions to the Knight shifts also come out too small. However, the orbital contributions to the Knight shift come out much better. This suggests that the copper 4{ital s} orbital is playing a non-negligible role, especially for the chain site. There the relaxation rate is linear in temperature and both the spin contribution and {ital T}{sub 1}{sup {minus}1} are roughly isotropic and approximately obey a Korringa relation. Simple estimates suggest that the Cu(1) and Cu(2) Knight-shift data as well as Cu(1) relaxation times could be explained by the presence of some 4{ital s} character at the Fermi level.

• OSTI ID: 6974401
• Journal Information: Physical Review, B: Condensed Matter; (USA), Journal Name: Physical Review, B: Condensed Matter; (USA) Vol. 41:16; ISSN PRBMD; ISSN 0163-1829
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360204* -- Ceramics
Cermets
& Refractories-- Physical Properties
ALKALINE EARTH METAL COMPOUNDS
BAND THEORY
BARIUM COMPOUNDS
BARIUM OXIDES
CHALCOGENIDES
COPPER COMPOUNDS
COPPER OXIDES
ENERGY LEVELS
FERMI LEVEL
HYBRIDIZATION
KNIGHT EFFECT
OXIDES
OXYGEN COMPOUNDS
RELAXATION
SPIN-LATTICE RELAXATION
TEMPERATURE DEPENDENCE
TRANSITION ELEMENT COMPOUNDS
YTTRIUM COMPOUNDS
YTTRIUM OXIDES