Robust critical behavior in YBa2Cu3O7 thin films

The nature of the vortex glass phase transition in thin film YBa2Cu3O7 is investigated by means of a scaling analysis of the I-V characteristics near T-g similar or equal to 70 K, in an applied field of 50 kOe. Exponents are found with nu similar or equal to 1.7 and z=5.0. By performing the analysis on temperature windows of varying widths about T-g, it is possible to determine whether scaling exponents and functions are consistent at different distances from T-g. In this way, scaling is found to be robust over a range of at least 17 K, in contrast to some recent analyses. No crossover to vortex glass Gaussian behavior is apparent throughout this range, or beyond it.