Observation of a thermal instability in niobium films having a local defect

A study was made of the destruction of the superconductivity by a transport current in niobium films with a bridge. When the temperature was sufficiently low, the current-voltage characteristics had a step and they matched the curves of the transition to the superconducting state at high currents. These results were explained by the formation of resistive domains in the films. The initial parts of the current-voltage characteristics demonstrated the importance of the activated thermal creep of the flux in niobium films