It had previously been reported, for Sr2+-doped material (0.035, 0.050 or 0.065mol% in the melt), that the interaction between a dislocation and an impurity could be approximated by the Fleischer model. However, from the values of φ0 for the specimens it was deduced that the Friedel relationship could be incorporated into the Fleischer model. Here, φ0 was the bending angle at which the dislocation engulfed the impurity under the effective shear stress at 0K. The interaction between a dislocation and an impurity could be approximated by the Fleischer model while account of the Friedel relationship. This was tested on the basis of the dependence of strain-rate sensitivity, due to impurities, upon temperatures of 100 to 200K. The critical temperature, at which the effective shear stress was zero, was found to be 282K. Values were also obtained for the enthalpy and for the Gibbs free energy of activation for the breakaway of dislocations from impurities.

Study of the Interaction between a Dislocation and Impurities in KCl:Sr2+ Single Crystals by the Blaha Effect I - Interaction between a Dislocation and an Impurity for Fleischer’s Model taking Account of the Friedel Relation. Y.Kohzuki: Journal of Materials Science, 2000, 35[13]. 3397-401