NQR and NMR in High Tc Superconductors

Abstract

AbstractRecent NQR and NMR experiments on La2-xSrxCuO4 , YBa2Cu3O7 , Tl2Ba2CuO6+y , and other compounds are reviewed. The antiferromagnetic spin fluctuations decrease in the order of La, Y, T1 compounds. In the normal state the T-dependence of (T1T)-1 is considered to follow the Curie- Weiss law at high temperature and the (Ti 7") = const law at low temperature. The T dependence of 1/T1 below Tc suggests strongly d-wave pairing. Correlations of the NQR frequency of 63Cu and 17O with the antiferromagnetic spin fluctuations and the superconducting transition temperature are discussed.