Correlation between different parameters of plastic deformation in doped NaCl crystals

The yield stress (τ_y), the microhardness (H) and the dislocation mobility in the stress field of a concentrated load (γ) were measured in NaCl: Ca and NaCl: Pb single crystals within the temperature interval 77–673 K. It was shown that there was a good correlation between the concentration changes of τ_y, H and γ for NaCl:Ca crystals. Such clear results were absent for NaCl:Pb single crystals. An anomaly of τ_y at 77 K was revealed for these crystals; it was not followed by the H anomaly. In conclusion it was stated that the impurity hardening was connected with the increasing of dislocation mobility but such a parameter did not determine the temperature hardening.