Formation of Two‐Dimensional Copper Selenide on Cu(111) at Very Low Selenium Coverage
| Autor: | Hyun Jin Yang, Holly Walen, Da-Jiang Liu, Patricia A. Thiel, Yousoo Kim, Junepyo Oh |
|---|---|
| Rok vydání: | 2016 |
| Předmět: |
Inorganic chemistry
chemistry.chemical_element 02 engineering and technology 010402 general chemistry 021001 nanoscience & nanotechnology 01 natural sciences Copper Atomic and Molecular Physics and Optics 0104 chemical sciences law.invention Crystallography Adsorption Lattice constant chemistry law Lattice (order) Density functional theory Physical and Theoretical Chemistry Copper selenide Scanning tunneling microscope 0210 nano-technology Selenium |
| Zdroj: | ChemPhysChem. 17:2137-2145 |
| ISSN: | 1439-7641 1439-4235 |
| DOI: | 10.1002/cphc.201600207 |
| Popis: | Using scanning tunneling microscopy (STM), we observed that adsorption of Se on Cu(111) produced islands with a (√3×√3)R30° structure at Se coverages far below the structure's ideal coverage of 1/3 monolayer. On the basis of density functional theory (DFT), these islands cannot form due to attractive interactions between chemisorbed Se atoms. DFT showed that incorporating Cu atoms into the √3-Se lattice stabilizes the structure, which provided a plausible explanation for the experimental observations. STM revealed three types of √3 textures. We assigned two of these as two-dimensional layers of strained CuSe, analogous to dense planes of bulk klockmannite (CuSe). Klockmannite has a bulk lattice constant that is 11 % shorter than √3 times the surface lattice constant of Cu(111). This offers a rationale for the differences observed between these textures, for which strain limits the island size or distorts the √3 lattice. STM showed that existing step edges adsorb Se and facet toward ⟨12‾ 1⟩, which is consistent with DFT. |
| Databáze: | OpenAIRE |
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