The measurement of grain boundary thickness using X–ray diffraction techniques

Abstract The three-dimensional reciprocal lattice of a large-angle [001] twist boundary in a gold bicrystal was examined using X–ray diffraction techniques. The intensity profiles of the relrods due to the thin grain boundary region were measured and the grain boundary thickness was determined from the inverse of the width of the peaks. The boundary thickness was estimated from several intensity profiles to be ∼ 8 a, which agrees well with the O–lattice period in the plane of the boundary. The detailed shape of the intensity profile for a particular relrod depends in a complicated fashion on the atomic displacements associated with the boundary region. As an indication of the complications that can arise it is noted that one peak gave a thickness of approximately one–half that measured from the other peaks. At present the variation in peak width for different relrods is not understood.