本文選題：手性型硅納米管 + 密度泛函　； 參考：《新疆師范大學(xué)》2017年碩士論文

【摘要】：通過密度泛函理論,對手性型硅納米管核團(tuán)簇的幾何構(gòu)型、核團(tuán)簇衍生過程以及無限長的手性型單、雙、三壁硅納米管的電子特性進(jìn)行了研究。詳細(xì)描述了研究的主要過程。首先描述手性型硅納米管核團(tuán)簇的幾何構(gòu)型;其次,研究核團(tuán)簇的衍生規(guī)律,經(jīng)分析得出由核團(tuán)簇生長為手性型硅納米管是通過逐層生長的方式進(jìn)行的;接著通過手性型硅納米團(tuán)簇的結(jié)合能,進(jìn)一步分析穩(wěn)定性與生長趨勢,經(jīng)分析表明手性型硅納米團(tuán)簇的穩(wěn)定性隨著長度和管徑的增加而增加,說明能夠得到手性型硅納米管;最后利用周期性邊界條件,得到無限長手性型硅納米管的結(jié)構(gòu),并通過結(jié)合能、能帶以及電子態(tài)密度研究其穩(wěn)定性與電子特性。經(jīng)分析表明:(1)手性型單壁硅納米管(n,n/2)的穩(wěn)定性隨著直徑增加逐漸增強(qiáng);手性型雙壁硅納米管(n,n/2)@(2n,n)的穩(wěn)定性隨著直徑的增加與管間距的增加逐漸增強(qiáng);手性雙壁硅納米管(2n,n)@(3n,3n/2)的穩(wěn)定性隨著直徑的減少與管間距的增加逐漸增強(qiáng)。(2)對單壁手性型硅納米管來說,若手性指數(shù)都是3的整數(shù)倍,則具有金屬性質(zhì);當(dāng)手性指數(shù)不是3的整數(shù)倍,則具有半導(dǎo)體性質(zhì),并且隨著管徑的增加帶隙逐漸減小。特別地,對管徑非常小的手性型硅納米管來說,由于曲率效應(yīng)會出現(xiàn)反常。例如手性指數(shù)為(4,2)和(6,3)的手性型硅納米管。雙壁、三壁手性型硅納米管與單壁手性型硅納米管的規(guī)律相同,即雙壁手性型硅納米管兩個(gè)壁的手性指數(shù)都是3的倍數(shù)或三壁手性型硅納米管三個(gè)壁的手性指數(shù)都是3的倍數(shù),則具有金屬性質(zhì),否則具有半導(dǎo)體性質(zhì)。特別地,雙壁手性型硅納米管(4,2)@(8,4),三壁手性型硅納米管(4,2)@(8,4)@(12,6)由于曲率效應(yīng)出現(xiàn)反常。此次研究是首次對手性型硅納米管進(jìn)行理論研究,可作為一個(gè)前期理論與方法的探索和積累,為實(shí)驗(yàn)研究提供一個(gè)思路、方向,為之后的研究進(jìn)行鋪墊和探索。
[Abstract]:The electronic properties of chiral silicon nanotubes were investigated by density functional theory (DFT), the geometric configuration of chiral silicon nanotubes, the derivation process of the clusters and the electronic properties of infinite chiral single, double and three-walled silicon nanotubes. The main process of the research is described in detail. Firstly, the geometric configuration of chiral silicon nanotube clusters is described. Secondly, the derivation law of the clusters is studied, and it is concluded that the growth of chiral silicon nanotubes from the clusters is carried out layer by layer. Then the stability and growth trend of chiral silicon nanoclusters were analyzed through the binding energy of chiral silicon nanoclusters. The results showed that the stability of chiral silicon nanoclusters increased with the increase of length and tube diameter, indicating that chiral silicon nanotubes could be obtained. Finally, the structure of infinite chiral silicon nanotubes is obtained by using periodic boundary conditions. The stability and electronic properties of the nanotubes are studied by means of binding energy, band and electron density of state. The results show that the stability of chiral single-walled silicon nanotubes increases with the increase of diameter, and the stability of chiral double-walled silicon nanotubes increases with the increase of diameter and spacing. The stability of chiral double-walled silicon nanotubes with 3nnnn-1 / 2) increases with the decrease of diameters and the increase of the distance between tubes. (2) for single-walled chiral silicon nanotubes, if the chirality index is 3 times, the chiral properties of the chiral nanotubes are metallic. When the chiral index is not an integral multiple of 3, it has semiconductor properties, and the band gap decreases with the increase of the diameter of the tube. In particular, for chiral silicon nanotubes with very small diameters, anomalies occur due to the curvature effect. For example, chiral silicon nanotubes with chiral index of 4 ~ 2) and 6 ~ 6 ~ 3). The chiral index of double wall chiral silicon nanotubes and single wall chiral silicon nanotubes is the same as that of single wall chiral silicon nanotubes, that is, the chirality index of two walls of double wall chiral silicon nanotubes is a multiple of 3, or the chirality index of three walls of three wall chiral silicon nanotubes is a multiple of 3. It has metal property, otherwise it has semiconductor property. In particular, the double walled chiral silicon nanotubes have an anomaly due to the curvature effect. This study is the first theoretical study of chiral silicon nanotubes, which can be used as a preliminary theory and method to explore and accumulate, to provide a train of thought for experimental research, and to pave the way for future research.
【學(xué)位授予單位】：新疆師范大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2017
【分類號】：TB383.1;O469

【參考文獻(xiàn)】

相關(guān)期刊論文 前7條

1 周超群;盛國平;;等溫滴定微量熱法測定腐殖酸與不同含氧量碳納米管的相互作用[J];中國科學(xué)技術(shù)大學(xué)學(xué)報(bào);2015年02期

2 于飛;周露;楊明軒;陳君紅;袁志文;馬杰;;柔性碳納米管透明導(dǎo)電薄膜國內(nèi)外研究進(jìn)展[J];功能材料;2012年15期

3 張靜;溫曉南;宋啟軍;金赫華;李紅波;李清文;;碳納米管透明導(dǎo)電薄膜制備技術(shù)的研究進(jìn)展[J];材料導(dǎo)報(bào);2011年05期

4 高紅,趙勇;納米材料及納米催化劑的制備[J];天津化工;2003年05期

5 高春華;納米材料的基本效應(yīng)及其應(yīng)用[J];江蘇理工大學(xué)學(xué)報(bào)(自然科學(xué)版);2001年06期

6 王廣厚;原子團(tuán)簇的穩(wěn)定結(jié)構(gòu)和幻數(shù)[J];物理學(xué)進(jìn)展;2000年01期

7 王廣厚;原子團(tuán)簇科學(xué)[J];科技導(dǎo)報(bào);1994年10期

，

本文編號：1950585