THE VORTEX-GLASS TRANSITION IN TL2BA2CACU2O8 SUPERCONDUCTING THIN-FILMS

We have measured the I-V curves of Tl2Ba2CaCu2O8 thin films at different temperatures in fixed magnetic field. The curves collapsed nicely onto two branches by plotting V/I/\T-T-g\(nu(z-1)) vs. I/T\T-g-T\(2 nu), with the temperature T-g, critical exponents nu and z determined from experiments. When T < 0.9T(g), the I-V curves collapsed onto a straight line by plotting log (R/R(min)) vs. -(I-min/I)(mu) with the exponent mu in the range of 0.27 to 0.50. These characteristics support the existence of a continuous phase transition at T-g from vortex-liquid to vortex-glass phase in Tl2Ba2CaCu2O8.