Computer Simulation of High-Resolution Electron Micrographs Using Dynamical Electron Scattering

A system of computer programs has been implemented that calculates both high-resolution images and diffraction patterns of generalized objects for the conventional transmission electron microscope. Multi-slice dynamical electron scattering of 256 × 256 = 65,536 beams is incorporated into these programs, which allows Bragg reflections and the diffuse scattering contributions between these reflections to be included in the computations. Images can therefore be obtained from imperfect crystalline structures and for disordered objects such as amorphous materials. Both bright- and dark-field images are obtained with this system in either the axial or tilted-beam imaging modes. Examples of surface effects in Au crystals, the [111] split Crowdion interstitial in tungsten, and an amorphous Fe film model are considered in the context of dynamical electron scattering.