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| Identifier |
uch.chemistry.msc//2004mavrandonakis |
| Title |
Θεωρητική μελέτη νανοσωλήνων πυριτίου - άνθρακα |
| Alternative Title |
Theoretical investigation of Si - C nanotubes |
| Creator |
Mavrandonakis, Andreas
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| Abstract |
In the past 10 years, one-dimensional nanomaterials have attracted considerable attention for their potentional use in nanoelectronics. After the discovery of carbon nanotubes by Iijima in 1991, much scientific interest was focused on the physical and electronic properties of these new materials. Generally speaking there are two research directions: studying the properties of existing nanomaterials and designing new materials that present specific properties. Following the second direction, many research groups tried either to synthesize new nanotubes based on elements other than carbon or to theoretically model hypothetic tubes. In both cases the first candidate to substitute carbon was silicon. Chasing the second goal, Ledoux and his collaborators were the first that synthesized SiC nanotubes. Later, two more research groups produced Si-C nanotubes. These tubes had morphology similar to the structure of carbon tubes. However the structure of this new material was not absolutely clarified. The only fact is that this material is constituted by silicon and coal in equal percentage (50%). Thus, using ab initio methods, we propose structures for these new tubes and study their stability. The first principles techniques have also been applied successfully in the study of nanotubes, made of carbon or other elements. Also, we predict the electronic characteristics of these SiC nanotubes. Taking into account Density Functional Theory, we propose two different types of Si- C tubes that are created from pure carbon tubes after replacing half of the carbon atoms with silicon. In type 1 tubes, each carbon atoms is linked to three silicon atoms, while in type 2 tubes, each carbon atom is linked to two silicon atoms and another carbon atom. Our results show that type 1 tubes are more stable than type 2. However, type 2 tubes present important electronic characteristics that are not observed in type 1. The calculation of their electronic attributes is done for systems of infinite length and applying the theory of Tight Binding Molecular Dynamics.
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| Subject |
Nanotubes , silicon carbide , theoretical , computational , ab initio methods , DFT , Density Functional Theory , Density of States , DOS , νανοσωλήνες , καρβίδιο του πυριτίου , θεωρητική , υπολογιστική, προσομοίωση , μέθοδοι από πρώτες αρχές , Θεωρία του Συναρτησιακού της Πυκνότητας , Πυκνότητα Καταστάσεων |
| Issue date |
2004-04-01 |
| Date available |
2004-07-26 |
| Collection
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School/Department--School of Sciences and Engineering--Department of Chemistry--Post-graduate theses
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Type of Work--Post-graduate theses
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| Views |
202 |
Θεωρητική μελέτη νανοσωλήνων πυριτίου - άνθρακα
