本論文利用模擬方法建構極細鉬奈米線與二硫化鉬奈米線，並分析其結構、機械性質與熱性質。本研究內容分成兩個部份:
第一部份利用basin-hopping方法搭配tight-binding勢能預測出極細鉬奈米線之穩定結構，依不同線徑尺寸分成6-1、10-4與10-5-1三種鉬奈米線，之後利用分子動力學對鉬奈米線做模擬拉伸測試與熱穩定性質。經由分析鉬奈米線的機械性質結果可知，鉬奈米線具有良好的延性，其楊氏模數隨尺寸縮小而下降。在熱性質方面，三條奈米線之熔點大約介在1230K~2090K之間，這結果顯示，極細鉬奈米線具有相當良好的熱穩定性，並可應用在電子元件。
第二部份利用相同方法搭配Stillinger Weber (SW)勢能預測出極細二硫化鉬奈米線之穩定結構，兩條奈米線半徑分別為1Å與1.7Å，建立穩定結構後利用分子動力學探討二硫化鉬奈米線之機械性質與熱穩定性質，分析二硫化鉬奈米線的機械性質結果可得，二硫化鉬奈米線也具有良好的延性，並且楊氏模數隨尺寸縮小而下降，在熱穩定性方面，在熱性質方面，三條奈米線之熔點大約介在540K~650K之間，這結果顯示，二硫化鉬奈米線在室溫下仍會存在。
比較鉬與二硫化鉬奈米線與鉬奈米線之機械性質與熱穩定性質，在機械性質方面二硫化鉬具有較好的延性，而在熱穩定性質方面，兩種奈米線在室溫下皆會存在，比較結果鉬奈米線熔點較高，熱穩定性質較佳。

In this study, We use simulation method to build ultrathin Mo nanowires and MoS2 nanowires,and analysis their structure, mechanical properties, and thermal properties. I divided my study into two part:
First the structure of ultrathin Mo nanowires were predicted by the simulated annealing basin-hopping method (SABH) with the tight-binding potential. Depending on different size of diameter it will divide into 6-1, 10-4, 10-5-1 three type. The mechanical properties and thermal stability of Mo nanowires were further examined by the molecular dynamic (MD) calculation. The mechanical properties results of nanowires are presented that Mo nanowires possess good ducility and their young’s moduli decrease with deacreasing size. In term of thermal sability, these Mo nanowire melting point will at 1230K~2090K, it can applicate as electronic device.
Second the structure of ultrathin MoS2 nanowires were predicted by the simulated annealing basin-hopping method with the stilliger-weber potential. The mechanical properties and thermal stability of MoS2 nanowires were further examined by the molecular dynamic calculation. The mechanical properties results of nanowires are presented that Mo nanowires also possess good ducility and their young’s moduli decrease with deacreasing size. In term of thermal sability, these Mo nanowire melting point will at 540K~650K, it will presence at room temperature.
Compare Mo nanowires and MoS2 nanowires, in mechanical properties two kind of nanowires, Mo nanowires possess good ducility. But in thermal properties both two kind of nanowires will presence at room temperature, Mo nanowires has good thermal stability.

論文審定書 i
致謝 ii
中文摘要 iii
英文摘要 iv
目錄 vi
圖次 viii
表次 x
第一章 緒論 1
1.1 研究目的與動機 1
1.2 鉬一維奈米結構文獻回顧 3
1.2.1 鉬一維奈米結構文獻回顧 3
1.2.2 二硫化鉬一維奈米結構文獻回顧 4
1.3 本文架構 7
第二章 模擬方法與理論介紹 8
2.1 分子靜力學理論 8
2.1.1 Big-bang計算法 8
2.1.2 Basin-hopping計算法 9
2.1.3 懲罰函數(Penalty function) 11
2.1.4 勢能函數 (Potential function) 12
2.2 密度泛函理論(DENSITY FUNCTIONAL THEORY, DFT) 16
2.2.1 電子密度 16
2.2.2 托馬斯-費米模型(Thomas-Fermi model) 17
2.2.3 霍恩貝格-柯恩理論(Hohenberg-Kohn model) 17
2.2.4 柯恩-軒姆方程式(Kohn-Sham equation) 18
2.2.5 交換相關函數(Exchange-Correlation Function) 20
2.3 分子動力學理論基礎及方法 22
2.3.1 積分法則 23
2.3.2 時間步階選取 24
2.3.3 系綜(Ensemble) 25
2.3.4 諾斯-胡佛恆溫法(Nosé-Hoover) 26
2.4 原子級應力分析 28
2.5 原子距離變化量統計 32
第三章 結果與討論 33
3.1 鉬奈米線幾何結構分析 34
3.2 鉬奈米線之機械性質分析 35
3.3 鉬奈米線之熱穩定性質分析 38
3.5 二硫化鉬奈米線之機械性質分析 42
3.6 二硫化鉬奈米線之熱穩定性分析 46
3.7 鉬與二硫化鉬奈米線機械性質與熱穩定性質比較 49
第四章 結論與建議 50
4.1 結論與建議 50
4.2 未來展望 52
參考文獻 53

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