Manifestation of vortex depinning transition in nonlinear   current-voltage characteristics of polycrystalline superconductor   Y_{1-x}Pr_{x}Ba_2Cu_3O_7
  We present our recent results on the temperature dependence of current-voltage characteristics for polycrystalline Y_{1-x}Pr_{x}Ba_2Cu_3O_7 superconductors with x = 0.0, 0.1 and 0.3. The experimental results are found to be reasonably well fitted for all samples by a power like law. According to the theoretical interpretation of the obtained results, nonlinear deviation of our current-voltage characteristics curves from Ohmic behavior below Tc is attributed to the manifestation of dissipation processes related to the current induced depinning of Abrikosov vortices. 
V.A.G. Rivera, C. Stari, S. Sergeenkov, E. Marega, F.M. Araujo-Moreira