Nuclear Resonance Properties of YBa2Cu3O6+x Superconductors.
Nuclear magnetic resonance (NMR) and nuclear quadrupole resonance (NQR) results for copper-63, oxygen-17, and yttrium-89 nuclei in the superconducting composition range of YBa(2)Cu(3)O(6+x) (0.4 </= x </= 1.0) are reviewed and interpreted. Copper NMR shift and susceptibility data, combined with a simple ionic model of local magnetic properties, yield a comprehensive analysis of the normal-state anisotropic susceptibility components and full characterization of the copper spin and orbital hyperfine couplings. Data on the spin-lattice relaxation time of these three nuclear species serve to characterize the highly correlated fermion dynamics in this system. Relaxation data from YBa(2)Cu(3)O(7) (superconducting transition temperature T(c) = 90 K) and oxygen-deficient samples of this material (T(c) approximately 60 K) have been analyzed in terms of meanfield models incorporating short-range antiferromagnetic order, giving a quantitative account of (planar) relaxation for these three nuclei in terms of a single dynamical susceptibility.
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