First-principles calculations of Cu(001) thin films: quantum size effect in surface energetics and surface chemical reactivities

摘要

First-principles calculations of Cu(001) free-standing thin films have beenperformed to investigate the oscillatory quantum size effects exhibited insurface energy, work function, atomic relaxation, and adsorption energy of thecesium adsorbate. The quantum well states have been shown and clarified atparticular $k$-points corresponding to the stationary extrema in bulk Brillouinzone, which are in good agreement with experimental observations. Thecalculated surface energetics and geometry relaxations are clearly featured byquantum oscillations as a function of the film thickness of the film withoscillation periods characterized by a superposition of long and short lengthscales. Furthermore, we have investigated Cs adsorption onto Cu(001) thin filmsas a function of the film thickness. Our systematic calculated results clearlyshow the large-amplitude quantum oscillations in adsorption energetics, whichmay be used to tailor catalysis, chemical reactions and other surface processesin nanostructured materials.