Font Size: a A A

First-Principles Study Of Carbon Nanotubes

Posted on:2005-06-23Degree:MasterType:Thesis
Country:ChinaCandidate:Y L MaoFull Text:PDF
GTID:2121360125969420Subject:Condensed matter physics
Abstract/Summary:PDF Full Text Request
Carbon nanotube is a hotspot and frontier of material researchand condensed matter physics in recent years. Because of itsmesoscopic dimension and novel physical and chemical properties,carbon nanotubes are considered to be of high theoretical values.Viewed by its great possibility on practical application, carbonnanotubes have been attracted considerable research interests forwhich directly related to nanotechnology. In terms of experimentalstudy, such as STM, Raman, and optical absorption et al, variousspecific structures and fantastic properties of carbon nanotubes havebeen found. In order to provide further insight into the structures andphysical properties, it is necessary to research them by usingtheoretical simulation methods. In this thesis, we investigate theviability and electronic properties of ultrathin carbon naontubes, aswell as carbon nanotubes doped with boron and nitride atoms usingfirst-principles method which is based on Density Function Theory(DFT). The thesis is organized as follows. In the introduction, thecalculated methods and purpose of our study are briefly introduced. Firstly, the basic knowledge of carbon nanotubes are introduced,which includes its discovery, geometrical structure, properties andapplications. In chapter II, the first-principle computation software CASTEP,which is based on the Density Function Theory (DFT), is introduced.The program structure, application process and computation functionare concluded. In chapter III, the smallest carbon nanotube (2, 2), which hasbeen found recently, is investigated. The stability of (2, 2) carbon iinanotube in multi-wall tubes and its electronic properties are studied. In chapter IV, we study the thermal stability of ultrathin carbonnanotubes, analysised the geometrical structure of the ultrathin carbonnanotubes which are stable. Especially, the electronic properties of 3? carbon nanotubes is investigated. In charpter V, the structural and electronic properties of B and Ndoped carbon nanotube are studied in detail. Moreover, we discuss therole of charge transfer in forming the acceptor and donor state incarbon nanotubes. In summary, a final conclusion is drawn for all the resultsobtained and a simple perspective of possible improvement on relativefield is described.
Keywords/Search Tags:Density functional theory, First-principle, Carbon nanotubes, Electronic structure
PDF Full Text Request
Related items