Molecular Dynamics Simulation of formation process of single-walled carbon nanotubes

Date & Time
26 October 2006 (Thu), 2:30 pm - 4:00 pm
6F seminar room, Sengen site
Dr. Yasushi Shibuta(澁田靖博士)
Department of Materials Engineering, University of Tokyo(東京大学大学院工学系研究科マテリアル工学専攻)
Molecular Dynamics Simulation of formation process of single-walled carbon nanotubes
Several remarkable properties of Single-walled carbon nanotubes (SWNTs) are attractive such as a metal-semiconductor duality determined by its chirality and a high thermal conductivity. In addition to initially developed laser-furnace technique by Smalley’s group in 1996, a catalytic chemical vapor deposition (CCVD) method enabled the large-scale production of SWNT. However, the diameter and chirality control is still unrealistic. The formation mechanism of SWNT has been widely discussed since its discovery. However, it is difficult to reproduce the entire formation process of SWNTs due to computational limits on the system size and time scale.
Hence, the formation process of SWNTs is studied by molecular dynamics simulation using novel many-body potential functions between carbon atoms and catalytic metal atoms constructed by fitting binding energies from DFT calculation.
単層カーボンナノチューブ(SWNT)は,その直径と巻き方(カイラリティ)によって導電体や半導体となる等の電気的特性,高い熱伝導特性などが期待されている材料である. 1996年,Smalleyらによるレーザーオーブン法によるSWNT大量合成の成功以来,現在までに触媒CVD法により,大量合成に関しては現実味を帯びてきたが,直径やカイラリティを制御する方法は未だ分かっていない.SWNTの生成機構についても長年議論されており,理論,数値計算によるアプローチが求められるが,系の時空間スケールが現在の計算機能力を超えており,何らかの近似が必要となるのが現状である.
Dr. Machiko Ode (大出真知子)