Stable MoSi2 nanofilms with controllable and high metallicity

Abstract

We use density functional theory calculations to show nanofilms of covalent MoSi2 exhibit tunable carrier densities and high metallicity at the Fermi level. We determine the nanofilm stabilities by assessing their formation energies, surface energies, and phonon spectra. The dependence of metallicity on the nanofilm geometry is explained using surface-termination-induced electronic structure changes and confinement effects. Understanding this metallicity not only is important to further improve the oxidation resistance of related alloys, but also will facilitate the identification of various thin films of MoSi2 alloys and should lead to their use in nanoelectronic, electrochemical catalysis and low-dimensional transport experiments.