The interaction force between the tetragonal defects and edge dislocations in the rock salt structure

Abstract

Abstract From the definition of the dipole tensor in the approximation of a linear continuum theory, the interaction energy between a dislocation and a point defect is found to depend on the average ionic volume. This interaction energy is used to derive the expressions for the elastic interaction force between 〈110〉 and 〈100〉 elastic dipoles with an edge dislocation gliding in either the (100) [011] or the (ī10) [110] slip system of the rock-salt structure. The maxima of the elastic forces are obtained from previous calculations and the flow stress of alkali halide crystals could be estimated. For the system NaCl:Ca, the contribution of each type of elastic dipole to the flow stress is shown to be the same, the agreement between the experimental and the theoretical specific hardening being about 10%. Finally, as the interaction energy between a dislocation and a point defect does not depend on the defect volume, it is shown that the flow stress of these crystals is insensitive to the formation of small c...