权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Dynamics of nanomaterials in electron beam processing

电子束加工中纳米材料的动力学

基本信息

批准号：
18560341
负责人：
YASUDA Masaaki
金额：
$ 2.35万
依托单位：
Osaka Prefecture University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2006
资助国家：
日本
起止时间：
2006 至 2007
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-18560341/
关键词：
electron beam fabrication nanocarbon carbon nanotube molecular dynamics Monte Carlo method electron irradiation effect electron irradiation damage 電子ビーム照射効果照射損傷電子顕微鏡分子動力学

项目摘要

Molecular dynamics studies are carried out to establish an electron beam fabrication technique for nanomaterials. We have developed a new simulation model which includes the interaction between a high energy incident electron and a target atom based on Monte Carlo method using the elastic scattering cross section. The scattering angle of the electron is determined by the Rutherford cross section. Then, the transferred energy from the electron to the target atom and the scattering angle of the atom are obtained based on the elastic scattering theory. The collision atom in the target materials is uniformly selected using a random number. Under the electron irradiation, the motion of each atom in the target is calculated with molecular dynamics simulation.The electron irradiation effects in carbon nanomaterials are studied with the simulation and the following results are obtained.1. The enhancement of the irradiation damages with the increase in the primary electron energy and the structural transition to amorphous-like structure by the electron irradiation are observed in the single-walled carbon nanotubes.2. The cross-links among neighboring material components are observed as typical irradiation damages in the multi-walled carbon nanotubes and the graphite.3. At high electron energy, some of the punched-out carbon atoms have enough energy to punch out another carbon atom in the structure.4. The structural changes such as the breakage, welding and bending of the single-walled carbon nanotubes are observed by the focused electron beam irradiation.

通过分子动力学研究，建立了纳米材料电子束制备技术。基于蒙特卡罗方法，利用弹性散射截面建立了包含高能入射电子与靶原子相互作用的模拟模型。电子的散射角由卢瑟福截面决定。然后，根据弹性散射理论，得到了电子向目标原子传递的能量和原子的散射角。用随机数均匀选择目标材料中的碰撞原子。在电子辐照下，用分子动力学模拟方法计算了靶内各原子的运动。通过模拟研究了碳纳米材料中的电子辐照效应，得到了以下结果：在单壁碳纳米管中观察到辐照损伤随一次电子能量的增加而增强，并且在电子辐照下结构向非晶结构转变。在多壁碳纳米管和石墨中观察到相邻材料组分之间的交联是典型的辐照损伤。在电子能量高的情况下，一些被击出的碳原子有足够的能量来击出结构中的另一个碳原子。通过聚焦电子束辐照，观察了单壁碳纳米管的断裂、焊接和弯曲等结构变化。