臺灣博碩士論文加值系統

摘 要
我們使用基本原理分子動力方法 ﹝ab initio molecular dynamics methods﹞，來探討氣態碳原子以不同的初始速度在C (100) 表面的附著性質。考慮選取三種初始速度分別為：0.0082, 0.0117 和0.0185 ，最大的初始速度對應到動能為0.43eV，此值用來和1eV數量級的化學吸附能﹝chemisorption energy﹞做比較。從選取的三種初始速度中，經由計算發現氣態碳原子都能輕易地附著在C (100) 的表面，尤其具有很大的初始速度的氣態碳原子，更能比較快速地附著在表面。這種情形可歸因於氣態碳原子的動能能有效地轉換給氫原子。我們發現當氣態碳原子的初始速度越高，它穿透到基片﹝substrate﹞深度就越深，使得氣態碳原子停留在接近撞擊位置。

Abstract
We have performed ab initio molecular-dynamics (MD) calculations for the dependence of the sticking property of a C gas-phase atom ( ) on C(100) on the initial velocity. We have considered initial velocities of 0.0082, 0.0117 and 0.0185
. The largest velocity considered corresponds to a kinetic energy of 0.2142 eV, which is comparable with the chemisorption energy of an order of 1eV. For the three initial velocities
considered, can settle on C(100) easily.
The relatively quick settlement of even with a large initial velocity can be attributed to an efficient transfer of kinetic energy from to the H atom. We also find that the higher initial velocity, the deeper penetrates into the substrate, which renders to stay closer to the impact position.

Contents
Ⅰ. Introduction ………………………………………….1
Ⅱ. Theory …………………………………………….…3
1. Density-function theory (DFT) ………………..……3
2. Local-density approximation (LDA) ………………11
3. ab initio molecular dynamics technique ………...12
Ⅲ. Calculational Details ……………………………..…20
Ⅳ. Results and discussion ………………………………23
Ⅴ. Summary ………………………………………..…..26
Ⅵ. Reference …………………………………………...27
Ⅶ. Figure captions ……………………………….…..…28

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