(383c) The Growth of Thin Metal Films on Polar Metal Oxides Surfaces: Insights from First-Principles Calculations

The growth of thin metal films and nanostructures on metal oxide supports is important in a range of technologies including microelectronics and catalysis. The morphology of the thin metal film will be dictated by interface strain, interface strength, and metal-metal binding strength. Density Functional Theory (DFT) affords the opportunity to obtain this information and to screen potential metal/metal oxide interfaces for optimal epitaxial growth. Due to the chemical inhomogeneity of the bulk structure, metal oxide surfaces can be cleaved to yield polar or non-polar surfaces. Polar surfaces, obtained if the repeat unit normal to the surface has a net dipole, are more predominant and have been shown to bind metals more strongly. We have examined the adsorption and growth of various thin metal films on the unreconstructed polar and non-polar low-Miller index surfaces of SrTiO3 and LaAlO3 using Density Functional Theory (DFT). We find a large range of interface strengths based on the polarity of the surfaces. Based on these results we will present an simple criteria to predict the relative strength of metal/metal-oxide interfaces based simply on DFT bulk atomic charges.