STUDY OF DISLOCATION LOOPS IN ALKALI HALIDE CRYSTALS BY DIFFUSE X-RAY SCATTERING

Overview & Synopsis

It has been known for some time that characteristic intensity oscillations occur in diffuse scattering patterns due to the displacement field of strong defects like clusters and dislocation loops. Besides the scattering of the displacement field the core structure of extended defects may cause an extra line close to the Bragg-peak. Only recently it has been found theoretically that for dislocation loops there is a correlation between oscillations and the extra line. The position of the extra line relative to a nearby reciprocal lattice point depends on the orientation of the Burgers vector and the reciprocal lattice vector as well. X-ray diffuse scattering results on irradiated alkali halide crystals containing large defect clusters are presented. Results are discussed in terms of loops with dose — dependend size.