FAVORABLE SILICA MONOLAYER STRUCTURES ON THE Mo(112) SURFACE

Favored structures of SiOn monolayers on Mo(112) surface have been studied using the total energy minimization technique based on DFT semirelativistic approach. In the [SiO4] complexes, which form the c(2 × 2) silica structure on the Mo(112), the bonding of the Si atoms with the surface is accomplished through the oxygen atoms. The structure with a symmetric position of oxygen atoms has been found to be the most favorable. In this structure, two oxygen atoms occupy bridge-on-row sites on the Mo(112) surface, with Si atoms between them, while oxygen atoms in the troughs appear not in expected threefold sites, but adjust their positions along the middle lines of the troughs. Estimated main phonon frequency and density of states for the symmetric [SiO4] structure agree well with experimental results.