Interpreting atomic resolution spectroscopic images

Abstract

Core-loss electron energy loss spectroscopy is a powerful experimental tool providing information about electronic structure essential for understanding the properties of new and emerging materials. Here we show that the shape and width of spectroscopic images do not show a simple variation with binding energy, as commonly assumed. Rather they exhibit a complex dependence on the effective nonlocal scattering potential, and also on the dynamical channeling and absorption of the incident probe through the specimen. Consequently, in LaMnO$_3$, the low lying La N$_{4,5}$ edge at 99 eV can produce images of similar width to higher lying edges such as the O $K$ edge at 532 eV.