Diffraction from void and bubble arrays in irradiated molybdenum

Abstract

Electron diffraction patterns from irradiated molybdenum specimens containing periodic arrays of voids or helium gas bubbles have been studied. It has been demonstrated that the void or bubble arrays act as diffraction gratings and produce extra reflections centred around the molybdenum matrix reflections. This technique enables a rapid evaluation to be made of the average void lattice parameter, and it is shown to be particularly useful for the study of arrays where spacing measurements are not feasible from micrographs of the direct images. It is pointed out that an important potential application of the technique, is for the study of ordered arrays of sub-microscopic defects.