I.F. Schegolev, N.N. Kolesnikov, V.N. Kopylov,
T.G. Tagonidze, O.M. Vyasilev.
On a possible reason of Tc suppression with
oxygen doping in Tl2Ba2CuO6+x.
Magnetic susceptibility and
63Cu and 205Tl nuclear spin-lattice relaxation
rates have been measured in Tl2Ba2CuO6+x
high- temperature superconductor to establish the mechanism of decreasing
the transition temperature with oxygen doping. The experiments have revealed
the presence of localized paramagnetic centers (LPC) whose concentration
grown with increasing oxygen content. These centers can give rise to magnetic
scattering of the Cooper pairs and thus be responsible for the Tc
suppression. This assumption is supported by the pair-breaking effects
observed in the NMR Knight shift and relaxation rate behavior in the superconducting