Growth and dislocation characteristics of organic molecular crystals: 2,3-dimethylnaphthalene

Abstract

Dislocation-free crystals of 2,3-dimethylnaphthalene were grown from a melt by the Bridgman method. The characteristics and motion of dislocations in the crystals were investigated by X-ray topography. The dislocations developed and expanded from highly strained regions in the crystals when they were annealed at higher temperature (102°C) just below the melting point (107°C). In the case of annealing at 60 and 80°C, no motion of dislocations was observed. The Burgers vectors of the moving dislocations were identified to be parallel to the [1 1 0] and [0 1 0] direction. The [1 1 0] (0 0 1) and [0 1 0] (0 0 1) system, therefore was suggested as one of the slip systems.