Atomic number contrast in high angle annular dark field imaging of crystals

Quantitative comparisons between experimental and simulated high angle annular dark field (HAADF) images of SrTiO3, PbTiO3, InP and In0.53Ga0.47As in the scanning transmission electron microscope (STEM) are presented. Significant discrepancies are found in the signal to background ratios. For these strongly scattering samples, spatial incoherence and instabilities cannot account for the bulk of this discrepancy, as they could in previous explorations on silicon. The authors discuss where additional experiments and theoretical studies are needed for developing a quantitative understanding of HAADF image contrast.