  In this study, we have used a Zr-Nb alloy containing well-defined
nano-precipitates as a model material in which to study imaging contrast
inversions (atomic number or diffraction contrast) observed with the
forescattered electron imaging system, ARGUSTM, in a scanning electron
microscope (SEM) when imaging a thin foil in a transmission geometry. The study
is based on Monte Carlo simulations and analysis of micrographs experimentally
acquired under different imaging conditions. Based on the results, imaging
conditions that enhance atomic number or diffraction contrast have been
proposed. Data acquired from the ARGUSTM imaging system in SEM has also been
compared with results from standard transmission electron microscopy and
scanning transmission electron microscopy imaging of the same material. These
results demonstrate the capability of the ARGUSTM system to investigate
microstructures in nano-scale materials.
