Carbon Nanotubes Grow on the C Face of SiC (0001̄) during Sublimation Decomposition: Quantum Chemical Molecular Dynamics Simulations
| Autor: | and Michiko Kusunoki, Stephan Irle, Guishan Zheng, Zhi Wang, Keiji Morokuma |
|---|---|
| Rok vydání: | 2007 |
| Předmět: |
Materials science
Graphene Nucleation Carbon nanotube Surfaces Coatings and Films Electronic Optical and Magnetic Materials law.invention Molecular dynamics General Energy Tight binding Chemical physics Computational chemistry law Atom Sublimation (phase transition) Surface layer Physical and Theoretical Chemistry |
| Zdroj: | The Journal of Physical Chemistry C. 111:12960-12972 |
| ISSN: | 1932-7455 1932-7447 |
| DOI: | 10.1021/jp072208d |
| Popis: | High-temperature quantum chemical molecular dynamics simulations (QM/MD) based on the density functional tight binding (DFTB) method were performed on SiC surfaces and compared with experimental observations. Following the nucleation of nanocaps on the C face of SiC(0001), substantial carbon nanotube (CNT) growth is observed during evaporation of Si between 2000 and 3000 K, while the Si face appears not capable of nanocap formation and perpendicular tube growth under otherwise identical conditions. Instead, graphene sheet growth parallel to the surface is observed in this case. Si evaporation is modeled by two approaches to Si atom removal, one where all Si atoms in one surface layer are removed simultaneously and another one where Si atoms are individually removed from random positions in selected surface layers. The tubes directly “grown” in our simulations display many sidewall defects, consistent with experimental findings. During random removal of Si on the C face, we also observe first indications ... |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|