High temperature dislocation mobility in LiF part I. Charged dislocations in ionic crystals

Abstract

The theory of electric charges on dislocations in ionic crystals is examined in light of the existing experimental observations of dislocation charge effects. A synthesis of these findings reveals that dislocations may possess either a positive or negative charge depending on the temperature and the concentration and the state of aggregation of the impurities. The charge of the dislocation is compensated by the presence of a “Debye - Huckel” cloud of point defects which surrounds the dislocation and imposes a drag force when the dislocation moves. These properties of charged dislocations are reviewed in an effort to provide a basis for the theory of high temperature glide mobility presented in the following paper.