Interpreting atomic-resolution spectroscopic images

Abstract

Core-loss electron energy loss spectroscopy is a powerful experimental tool with the potential to provide atomic-resolution information about electronic structure at defects and interfaces in materials and nanostructures. Interpretation, however, is nonintuitive. Comparison of experimental and simulated compositional maps in LaMn O3 shows good agreement, apart from an overall scaling of image contrast, and shows that the shape and width of spectroscopic images do not show a simple variation with binding energy, as commonly assumed, or with the size of the orbital excited. For the low lying La N4,5 edge with threshold at around 99 eV, delocalization does not preclude atomic resolution, but re..