Self-interstitial atoms at high temperatures in dense metals

It has long been clear that vacancies are usually the most abundant defect in equilibrium in most dense, close-packed metals. However, some important effects, such as the observed deviation of the diffusion coefficient. from pure Arrhenius behaviour, can not be explained by invoking only a single va cancy. The most common explanation to the deviations is that also divacanci es, and possibly even trivacancies, play a significant role. However, some evidence also indicate that interstitials could play a significant role. In this article, we review surae recent work and our computer simulation resu lts on this issue. Both the reviewed work and simulations point in the dire ction that the interstitial could be of major importance close to the melti ng temperature and during rapid heating. The results also strongly support the Granato model of liquids and solids.