The results of 139La and 63Cu nuclear quadrupole resonance (NQR) on La-Ba,Sr-Cu-O, Y-Ba-Cu-O, and Bi-Pb-Sr-Ca-Cu-O compounds and of 17O nuclear magnetic resonance (NMR) on Y-Ba-Cu-O are extensively reviewed. As for the magnetism, the phase diagram for the La system studied by a 139La NQR experiment is presented, with evidence of the disordered magnetic state between the 3D-antiferromagnetic (AF) ordered state and the superconducting state. With respect to its superconducting nature, the nuclear spin-lattice relaxation behavior (T1) of Cu in the CuO2 plane has been found to be unconventional above and below Tc for all compounds, with no signatures expected for a nonmagnetic metal and a BCS superconductor, respectively. The behavior of T1 of Cu above Tc is shown to be dominated by AF fluctuation of Cu d spins. In contrast, an enhancement of 1/T1 of 17O has been observed just below Tc, which is similar to a BCS case.
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