Vortex dynamics in a thin film of Tl2Ba2CuO6

The vortex dynamics in a Tl2Ba2CuO6 (Tl-2201) thin film with a critical temperature Tc = 80.8 K has been studied by electrical resistivity measurements for magnetic fields 0 le B le 12 T. The vortex glass line, as determined from the disappearance of linear resistivity, was found to be well described by Bg(T) = B0[(1 minus T/Tc)/(T/Tc)]α, with B0 ∼ 0.65 T and α ∼ 1.9. The glass line of Tl-2201 is observed to be located below the one of Tl2Ba2CaCu2P8δ (Tl-2212) in a magnetic phase diagram based on a reduced temperature scale T/Tc, thus suggesting a higher anisotropy for Tl-2201