Bayesian Statistical Model for Imaging of Single La Vacancies in LaMnO3

Previous simulation studies have demonstrated that single La vacancies can be detected using high precision quantitative high-angle annular dark-field (HAADF) Z-contrast scanning transmission electron microscopy (STEM) [1] by both the reduction in scattered intensity created by the missing atom and the distortion of the surrounding atom positions [2]. We have now experimentally detected single La vacancies on nominally stoichiometric LaMnO3 films grown on DyScO3 substrate by molecular beam epitaxy with ~1% control of cation stoichiometry. The vacancy depth is determined from channeling behavior of the electron probe, quantified by a Bayesian statistical model that compares experiments to a library of simulations