From 1967 to 2000 Daniel Louër of the Department of Crystal Chemistry, University of Rennes, and J. Ian Langford of the Department of Physics, University of Birmingham, collaborated in studying structural imperfections by means of high-resolution X-ray powder diffractometry. They contributed to the theory and practice of line profile analysis and investigated the microstructure of a variety of nanocrystalline materials. Although many of the projects undertaken were part of the research programme at Rennes to investigate the mechanisms of solid-state reactions, the work is relevant in other fields of materials science.
