| Citation | Distinguished for his pioneering contributions to the theory of transmission electron microscope image contrast of lattice defects in crystals. Together with Whelan he was responsible for developing the dynamical theory of image contrast from dislocations. He made several outstanding contributions to our understanding of the effect on image contrast of inelastic scattering of electrons in crystals, and of the channelling of electrons and other particles in crystals. He was responsible for important theoretical developments relating to the weak beam technique of transmission electron microscopy, and to the contrast of defects observed by scanning electron microscopy. More recently he has applied with great effect high resolution electron microscopy to the study of the structure of amorphous materials. His work is characterised by its clarity, insight and elegance. |