Comparison of dislocation mobility in LiF measured by direct and indirect methods

A comparison is made of the effective stress dependence of the dislocation velocity V in LiF crystals as determined by stress relaxation tests and by direct etch pit measurements. The stress relaxation technique used permits to study both the effective stress dependence of V and the evolution of the total and mobile dislocation densities during the dynamic loading of the crystals. The data obtained by the two methods are in good agreement. It is shown that the density of mobile dislocations is decreasing with the strain, whereas the total dislocation density is growing during the dynamic straining to 1%. [Russian Text Ignored]