/sup 17/O NMR study of YBa/sub 2/Cu/sub 3/O/sub 7/minus/delta/

Conference · Sun Jan 01 04:00:00 EST 1989

OSTI ID:6052126

Takigawa, M; Hammel, P C; Heffner, R H; Fisk, Z; Ott, K C; Thompson, J D

We present our /sup 17/O NMR experimental results in a magnetically aligned powder sample of YBa/sub 2/Cu/sub 3/O/sub 7/minus/delta/ (T/sub c/ = 93 K). The sign of the anisotropic Knight Shift shows that the spin density resides mainly on the p/sub sigma/ orbitals at the planar O(2,3) and bridging O(4) sites. About 30 % of the total spin susceptibility is attributed to the oxygen 2p/sub sigma/ states. The Knight shift at the O(2,3) sites decreases more rapidly than that at the chain O(1) sites, indicating a larger gap in the planes. The nuclear relaxation rate at the O(2,3) sites shows linear-T (Korringa) behavior above T/sub c/, in contrast to the much temperature dependence at the planar Cu(2) sites. However, these two rates show identical temperature dependence below about 110 K, indicating that an important change in the spin dynamics takes place above T/sub c/. 13 refs., 3 figs.

• Research Organization: Los Alamos National Lab., NM (USA)
• DOE Contract Number: W-7405-ENG-36
• OSTI ID: 6052126
• Report Number(s): LA-UR-89-2141; CONF-890718-3; ON: DE89014292
• 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
CHALCOGENIDES
COPPER COMPOUNDS
COPPER OXIDES
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
EVEN-ODD NUCLEI
ISOTOPES
KNIGHT SHIFT
LIGHT NUCLEI
MAGNETIC RESONANCE
NUCLEAR MAGNETIC RESONANCE
NUCLEI
OXIDES
OXYGEN 17
OXYGEN COMPOUNDS
OXYGEN ISOTOPES
PHYSICAL PROPERTIES
RELAXATION
RESONANCE
SPIN-SPIN RELAXATION
STABLE ISOTOPES
SUPERCONDUCTIVITY
TEMPERATURE DEPENDENCE
TRANSITION ELEMENT COMPOUNDS
YTTRIUM COMPOUNDS