Ab initio transmission electron microscopy image simulations of coherent Ag-MgO interfaces

Density-functional theory calculations, within the plane-wave-ultrasoft pseudopotential framework, were performed in the projection for MgO and for the coherent {111} Ag-MgO polar interface. First-principles calculations were incorporated in high-resolution transmission electron microscopy (HRTEM) simulations by converting the charge density into electron scattering factors to examine the influence of charge transfer, charge redistribution at the interface, and ionicity on the dynamical electron scattering and on calculated HRTEM images. It is concluded that the ionicity of oxides and the charge redistribution at interfaces play a significant role in HRTEM image simulations. In particular, the calculations show that at oxygen-terminated {111} Ag-MgO interfaces the first oxygen layer at the interface is much brighter than that in calculations with neutral atoms, in agreement with experimental observations