MUON SPIN ROTATION STUDY OF THE CORRELATION BETWEEN T(C) AND N(S) M-ASTERISK IN OVERDOPED TL2BA2CUO6+DELTA/

The muon spin depolarization rate sigma was measured in overdoped Tl2B a2CuO6+delta. Sigma(T --> 0) was found to decrease proportional to the superconducting transition temperature T(c) as doping delta is increa sed. In the framework of the clean-limit London model, sigma(0) is sim ilar to lambda-2 is similar to n(s)/m, this implies that the depressi on of T(c) by overdoping is associated with a decrease of the supercon ducting condensate density n(s) in spite of the increasing normal-stat e carrier density. This can be largely accounted for in terms of stron g pair breaking, which depresses both the condensate density and T(c) with increased doping.