⁶³Cu and ¹⁷O NMR studies on the magnetic and superconducting properties of YBa ₂Cu ₃O _7-y

Abstract

Results of 63Cu and 17O NMR experiments in YBa 2Cu 3O 7 and YBa 2Cu 3O 6.63 are reviewed. The normal state data revealed two important aspects of the magnetic properties of these materials, namely, the temperature dependent antiferromagnetic Cu spin correlations and the spin gap behavior, the latter being observed in the reduced oxygen material. These features appear to be the general properties of many high-T c cuprates. Anomalous temperature dependence of the anisotropy of the Cu relaxation rate was found in the superconducting state of YBa 2Cu 3O 7, which can be explained by a d-wave pairing model. © 1992 Springer.