Critical fluctuations at the superconducting transition of TmBa2Cu3O7-delta thin films in transverse and longitudinal magnetic fields

We report an investigation of the resistive transition from the normal to the mixed state of TmBa2Cu3O7-delta thin films in different orientations of magnetic fields up to 13 T. The broadening of the transition and its specific shape obscures the superconducting phase transition line T-c(B). Using the renormalized theory for critical superconducting fluctuations in the anisotropic three-dimensional Ginzburg-Landau model by R. Ikeda we obtained an excellent description of the upper part of the resistive transition in transverse magnetic fields. In the longitudinal orientation, the broadening of the superconducting transition in a magnetic field is significantly smaller, in qualitative agreement with theory.