O.M. Vyasilev, N.N. Kolesnikov, I.F. Schegolev.
Transition from strong to weak coupling regime with
lowering Tc in Tl2Ba2CuO6+x.
Using 205Tl NMR, the changes
in electronic properties in the normal and superconducting state of the
Tl2Ba2CuO6+x compound associated
with variation of Tc, are studied in samples with
Tc=30, 100, and 115K. Decreasing Tc with
oxygen doping is shown to be associated with the growth of the static electron
spin susceptibility and with lowering the D/Tc
ratio (D is superconducting gap).
This effect indicates to the corresponding weakening of coupling regime.