DETERMINATION OF THE SIGN OF A DISLOCATION IN A ZNTE CRYSTAL BY CONVERGENT-BEAM ELECTRON-DIFFRACTION

The twist and distortion of diffraction fringes in a convergent-beam electron diffraction pattern, caused by a dislocation in a ZnTe crystal, have been studied systematically. It has been found that the sense of such a twist reverses when the beam crossover changes from one side of the specimen to the other. From a qualitative consideration, it has been concluded that the diffraction fringes on the side pointed to by the vector u x c are shifted along b. This phenomenon can be used to determine the sign of the Burgers vector of a dislocation.