The Imaging Of Surface Step Structures By Dark Field Electron Microscopy

SUMMARY The dark field imaging of monatomic surface steps is studied by weak beam electron microscopy using reflections in higher order Laue zones. Dynamical theory calculations of the step intensities and of the diffuse background intensity in various diffracting conditions are in moderately good agreement with experimental observation on (111) thin films of gold. From grooving effects visible at incoherent twin boundaries, the boundary energy is estimated to be about one‐third of the surface energy. The extension of the method to other crystal surfaces or other materials is discussed.