In order to check the Granato-Lücke theory, the internal friction and dislocation core current of single crystals were measured. Vacancies that moved in-phase with dislocation cores, and vacancies that underwent phase-delay by dislocations, were observed. Dislocations swept up vacancies on the slip plane with the break-away strain amplitude. The accuracy of the Granato-Lücke theory was demonstrated by subtracting the increase in friction, due to swept-up vacancies, from the measured values. Corrections could also be performed for samples where the number of vacancies had been changed by irradiation with γ-rays. The dislocation core of an irradiated sample was found to be negatively charged by an excess of vacancies in the low strain-amplitude regime.

Dislocation String Model and Sweep-up Vacancy. H.Tateno, Y.Hara: Japanese Journal of Applied Physics–1, 2004, 43[2], 715-9