L.N. Bulaevskii, N.N. Kolesnikov,
I.F. Schegolev, O.M. Vyaselev.
Effect of vortex fluctuations on 205Tl spin-lattice
relaxation in the mixed state of Tl2Ba2CuO6.
The spin-lattice relaxation rate W on 205Tl
has been measured in the mixed state of a Tl2Ba2CuO6
aligned powder sample with Tc=100 K. At T <
25 K, W µ T and decreases
with increasing magnetic field. This behavior is explained as caused by
fluctuations of pancake vortices; the latter induce a time dependent random
magnetic field which causes the relaxation of nuclear spins.