Morphology of copper nanoparticles in a nitrogen atmosphere: A first-principles investigation
| Autor: | Bernard Delley, Catherine Stampfl, Aloysius Soon, Lindee Wong |
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| Rok vydání: | 2008 |
| Předmět: | |
| Zdroj: | Physical Review B. 77 |
| ISSN: | 1550-235X 1098-0121 |
| DOI: | 10.1103/physrevb.77.125423 |
| Popis: | We perform first-principles density-functional-theory calculations to determine the stability and associated physical and electronic properties of different adsorption phases of N on Cu (100) and Cu (110) substrates for coverages ranging from 0.125 to 1 monolayer (ML). For N on Cu (100), we consider adsorption in fourfold hollow sites while for N on Cu (110), we consider various adsorption sites including N-induced missing-row surface reconstructions and the surface nitridelike, ``pseudo-(100)'' reconstruction. We report the atomic and electronic structure and compare with analogous results for N/Cu (111). By combining results from our previous study of the N/Cu (111) system with the current investigations, we predict the possible morphology of a Cu crystal in different nitrogen environments by performing a Wulff construction at appropriate chemical potentials of nitrogen. We also find that all low-energy N/Cu surface structures---namely, $\text{Cu}\text{ }(100)\text{\ensuremath{-}}c(2\ifmmode\times\else\texttimes\fi{}2)\text{-N}$ and the surface nitrides found on Cu (110) and Cu (111)---share a common geometric feature: i.e., surface nanopatterns resembling 1 atomic layer of ${\text{Cu}}_{3}\text{N}\phantom{\rule{0.3em}{0ex}}(100)$. These nanopatterned structures exist for a narrow range of nitrogen chemical potentials before the onset of bulk ${\text{Cu}}_{3}\text{N}$, unless kinetically hindered. This qualitative behavior of the predicted formation of thin-surface nitridelike structures prior to the bulk nitride material is very similar to that for transition-metal surfaces in an oxygen atmosphere, where surface oxidelike structures are predicted to be thermodynamically stable prior to bulk oxide formation. |
| Databáze: | OpenAIRE |
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