Structural exploration of thin-film oxide interfaces via ‘simulated amorphisation and recrystallisation’

Realistic atomistic simulation models of interfaces must include a sufficiently large simulation cell to accommodate the incommensurate relationship between the lattice parameters of the two materials, and include misfit-induced defects such as dislocations. In addition, the final structure must not be influenced artificially by the starting structure. Here we present a methodology, which satisfies such demands by performing large-scale atomistic simulations of thin-film oxide interfaces, which approach the meso-scale and involve amorphisation and recrystallisation of the thin film. The methodology is applied to the SrO/MgO(0 0 1) system, which was used as a model system representative of supported materials associated with a high lattice misfit. The final MgO(0 0 1) supported SrO thin-film structures comprise many dislocations (including mixed screw edge and pure edge), defects, reduced interfacial ion densities, commensurate domains and low angle rotated domains.