Structure and Configuration of Boundary Dislocations on Low Angle Tilt Grain Boundaries in Alumina

Abstract

Structure and configuration of boundary dislocations on various low angle tilt grain boundaries in alumina were considered based on the ideas that the boundary is composed of regularly arrayed edge dislocations and that the dislocations could dissociate into partial dislocations with maintaining the hcp-like oxygen sublattice. Moreover, the separation distance between the partial dislocations formed by the dissociation was evaluated by the calculations based on an elastic theory. The calculations indicated that the width of the stacking fault region between partial dislocations decreases with increasing tilt angles. As a consequence, the hypothesis and calculations used here would enable us to predict the structures of various low angle boundaries with dissociated boundary dislocations.