ON PLASTIC-DEFORMATION OF PB0.95SN0.05SE SINGLE-CRYSTALS

Stress-strain characteristics of Pb0.95Sn0.05Se single crystals grown from the vapour phase have been investigated in the plastic deformatio n range. Samples were compressed along a [100] direction, with strain rate varying between 1.85 x 10(-5) and 1.85 x 10(-3) s(-1), in the tem perature interval 300-573 K. Plastic deformation was found to include all three stages of deformation hardening and to be performed by slip of dislocations on the {110} [1 (1) over bar 0] slip system. In condit ions when deformation took place in a single-slip system, internal and effective stress values were determined in the easy-glide region. The stress relaxation method was used, taking into account the hardening in process of relaxation. The effective stress as a function of strain rate was found to obey a power law, while the temperature dependence had a thermally activated character. Values of activation parameters w ere found as a function of effective stress by thermal activation anal ysis. The results obtained are interpreted in the paper by a model of dislocation interaction with systems of intrinsic point defects in the lattice.