Phonon spectra of clean and Ni-terminated diamond (111) surfaces: An ab-initio study

Abstract The phonon densities of states (ph-DOSs) of clean and Ni-terminated C (111) surfaces with 1 × 1 and 2 × 1 surface structures were investigated using ab-initio density functional perturbation theory. The ph-DOSs showed vibrational spectra associated with the surface structures of C (111) and Ni/C (111). Further analyses of various surface phonon modes were performed to identify vibrational features involving the surface atoms of C (111) and Ni/C (111). These features provide important information for experimentally verifying the formation of a diamond bulk-like structure at Ni/C (111), as suggested in a previous study.