CU NUCLEAR SPIN-SPIN RELAXATION IN TL2BA2CUO6+DELTA

We have measured the temperature (T) dependence of the Gaussian decay rate 1/T-G associated with the Cu-63 nuclear spin-spin relaxation of Tl2Ba2CuO6+delta (T-c similar to 85 K) by the NMR spin-echo technique. 1/T-G increases from T-c up to T(sp)similar to 120 K and decreases monotonically in a Curie-Weiss-like law above T-sp. In spite of the nonmonotonic T-dependence of(1/T-G)(2) [similar to chi(Q)], we have found that (1/T-G)(2)scales to 1/T1T and hence 1/T-1 proportional to T chi(Q) is valid above T-c. This result indicates that the antiferromagnetic spin-fluctuation theory for the two-dimensional itinerant electron system holds for the present overdoped monolayered Cu oxide without a dynamical gap.