Thermal activation and viscosity

Creep behavior in superconductors is used to show how viscosity can affect thermally activated processes. In the case of a number of lead alloys the creep rate in the normal state is substantially less than in the superconducting state, in the temperature range where barriers control the creep process. This is explained through the temperature dependence of the electron damping of dislocations in the normal state compared to the superconducting state, and in the mixed superconducting state.