Measurements of Plastic Flow in Superconductors and the Electron-Dislocation Interaction

The increase in flow stress which occurs at the transition from the superconducting to the normal state has been measured as a function of work hardening, strain rate, and temperature in specimens of pure lead and indium. The results show that this flowstress increase is strain-rate independent and proportional to 1-(TTc)² to an accuracy of ±{} 5%. The lack of strain-rate dependence is inconsistent with the simple model which relates the flow stress to the viscous drag force required to move a dislocation through an electron gas.