Atomistic modelling of metal-oxide interfaces with image interactions

Abstract

Ag-MgO and Au-MgO interfaces in the (100) and (110) orientations have been modelled using the MIDAS code. Image interactions between the ions and the metal and short-range interactions between the metal atoms and ion cores are included. The short-range interactions are calculated using accurate Hartree-Fock methods. Classical image interactions are modified by suppressing fluctuations of the induced charge density which have wavelengths longer than the Fermi wave-vector. This approach eliminates the singularities which plague classical image models. The answers agree well with calculations performed using the local-density approximation (including, unfortunately, the poor prediction of the wetting angle). The predicted interfacial bonding energy is 0.8 eV (1·81 Jm⁻²).