LOW-TEMPERATURE PLASTICITY OF PB-BI ALLOYS - THE ROLE OF THERMAL-ACTIVATION AND INERTIAL EFFECTS

Detailed studies of temperature dependences of critical shear stress a nd strain-rate sensitivity of deforming stress of Pb-Bi single crystal s with 0.1-6.0 at. % Bi are carried out in the temperature range 0.5-2 95 K. The deforming stress decrease during a superconducting transitio n of the sample is studied and the concentration dependence of the eff ect is measured. The ideas of a gradual transition (upon cooling) from thermally activated motion of dislocations through impurity barriers to the thermoinertial mechanism in the temperature range 10-25 K and f urther to the quantum-inertial motion at temperatures less than or sim ilar to 1 K are developed. A detailed thermoactivation analysis of exp erimental data is carried out, and empirical estimates of internal str esses, dislocation-impurity interaction parameters, electron and phono n components of dynamic drag coefficient for dislocations are obtained . (C) 1998 American Institute of Physics. [S1063-777X(98)01108-6].