English  |  正體中文  |  简体中文  |  全文筆數/總筆數 : 46965/50831 (92%)
造訪人次 : 12817218      線上人數 : 500
RC Version 6.0 © Powered By DSPACE, MIT. Enhanced by NTU Library IR team.
搜尋範圍 查詢小技巧:
  • 您可在西文檢索詞彙前後加上"雙引號",以獲取較精準的檢索結果
  • 若欲以作者姓名搜尋,建議至進階搜尋限定作者欄位,可獲得較完整資料
  • 進階搜尋
    主頁登入上傳說明關於CCUR管理 到手機版


    請使用永久網址來引用或連結此文件: https://irlib.pccu.edu.tw/handle/987654321/32058


    題名: 有缺陷之三角形類石墨烯硼氮奈米結構之密度泛函數計算研究
    A Density Functional Study on the Defective Triangular Graphene-like BN Nanostructures
    作者: 邱珮盈
    貢獻者: 化學系應用化學碩士班
    關鍵詞: 石墨烯
    三角形奈米片
    硼氮三角形奈米片
    Graphene
    Triangular nanoflakes
    BN-TNFs
    日期: 2015
    上傳時間: 2016-02-24 14:25:05 (UTC+8)
    摘要: 石墨烯硼氮類似物稱為白石墨烯,本論文乃以密度泛函中的B3LYP法研究含缺陷之以硼為邊氮為頂的白石墨烯三角形奈米薄片(BN-TNFn),其中n = 4~6為每邊六角環數目。由於薄片尚不夠大,在中央地區挖掉一個B或N原子後,結構重建的結果會因邊緣效應普遍呈現非平面。當半徑相近的C或O原子吸附在重建的破洞上方後,平面結構仍難回復,但C較具有縫補破洞的效果,O反而造成更大破洞或結構扭曲,這是因為C可與四個原子鍵結,O只能與兩個原子鍵結的緣故。如果直接將中心B或N換成雜質C或O情形也類似,只是C取代時平面變形較不嚴重;若換成O,反而從沒有破洞變成有破洞,而且造成去平面化。從平均結合能來看,破洞被吸附之後的產物比直接取代的產物還穩定。然而,不管是單單只有破洞、有雜質吸附在破洞、或直接取代,BN-TNFn的磁性都大大降低。
    The boron nitride counterpart of graphene is the white graphene. In this thesis we employed the B3LYP method to investigate the B-edged (with N vertices) triangular nanoflakes of white graphene (BN-TNFn), where n = 4~6, being the number of hexagonal ring along each side. Because the area of BN-TNF4~6 are not wide enough, geometric reconstructions rendered non-planar species due to the edge effect after a vacancy was made by removing a central B or N atom. When an adatom C or O, which has similar sizes with B and N, was adsorbed by the reconstructed vacancy, the original flatness still could not be restored. However, C would stitch the hole, making it smaller, while O made the hole even larger and structure more distorted. This is because the bonding capacity of C and O are 4 and 2, respectively. Direct substitutions (doping) of a central B or N by C or O gave similar results. C-doping caused less structural distortion; however, O-doping opened a vacancy, making obvious structural changes. According to the mean binding energy, products from adatom adsorption were more stable than those from direct doping. Magnetism were greatly quenched by a vacancy, an adatom, and a dopant as compared to the pristine BN-TNF4~6.
    顯示於類別:[化學系所] 博碩士論文

    文件中的檔案:

    檔案 描述 大小格式瀏覽次數
    index.html0KbHTML408檢視/開啟


    在CCUR中所有的資料項目都受到原著作權保護.


    DSpace Software Copyright © 2002-2004  MIT &  Hewlett-Packard  /   Enhanced by   NTU Library IR team Copyright ©   - 回饋