Thermally Assisted Flux Flow in MgB2 : Strong Magnetic Field Dependence   of the Activation Energy
  The origin of the resistive transition broadening for MgB2 thin films was investigated. Thermally activated flux flow is found to be responsible for the resistivity contribution in the vicinity of Tc. The origin of the observed extraordinary strong magnetic field dependence of the activation energy of the flux motion is discussed. 
A.Sidorenko, V. Zdravkov, V. Ryazanov, S. Horn, S. Klimm, R.Tidecks,   A. Wixforth, Th. Koch, Th. Schimmel