Strain-rate cycling tests and Blaha-effect measurements were carried out at 80 to 300K on Li+-doped material (0.5mol% in the melt) and Na+-doped material (0.5mol% in the melt). An attempt was made to select the most suitable force-distance relationship between a dislocation and a monovalent cation impurity. The 3 candidate models were a square force-distance relationship, a parabolic one and a triangular one. By taking account of the Friedel relationship, the search for the most suitable force-distance law was pursued by considering 3 relationships: that between the effective stress and temperature, the dependence of the strain-rate sensitivity (due to impurities) upon temperature, and the proportionality of ΔH(T). The latter was the activation enthalpy for the interaction, between a dislocation and an impurity, as a function of temperature. The square force-distance relationship was concluded to be the most suitable one for KCl:Na+. It was difficult to select the most suitable relationship for KCl:Li+.

Groping for a Suitable Force-Distance Relation between a Dislocation and the Impurity for KCl:Li+ and KCl:Na+ by the Blaha Effect. Y.Kohzuki: Journal of Materials Science, 1998, 33[23], 5613-9