Quantitative comparisons of contrast in experimental and simulated bright-field scanning transmission electron microscopy images

摘要

Quantitative, atomic resolution bright-field scanning transmission electron microscopy experiments are reported. The image intensities are placed on an absolute scale relative to the incident beam intensity. Features in the experimental images, such as contrast reversals, intensities, and the image contrast, are compared with image simulations that account for elastic scattering and the effect of phonon scattering. Simulations are carried out using both the multislice absorptive and frozen phonon simulation methods. For a SrTiO_3 sample with thicknesses between 4 and 25 nm, both models agree within the experimental uncertainty. We demonstrate excellent agreement between the simulated and the experimentally observed image contrast. The implications for the contrast mismatch commonly reported for high-resolution transmission electron microscopy using plane-wave illumination are discussed.