Abstract
A method is described by means of which the intensities of the ‘Fresnel’ fringes observed in an electron microscope at a boundary with a small coincident site lattice displacement can be used to measure the component of this displacement perpendicular to the boundary. Full atomistic image simulations are required for such determinations and the general trends of fringe visibility with specimen thickness, objective defocus and crystallographic orientation are theoretically assessed and compared with experimental data for 3(111) twin boundaries in copper.