【摘要】：由于電子元器件和機(jī)械微型化的巨大發(fā)展和推動,人們越來越重視對納米材料結(jié)構(gòu)的基礎(chǔ)研究。當(dāng)材料的尺寸降低到納米尺寸(約100nm),由于量子尺寸效應(yīng),它們的各種物理化學(xué)性質(zhì)甚至生物活性等都變得非常奇特。基于可控的材料制備、結(jié)構(gòu)和特性研究,人們渴望能根據(jù)環(huán)境和性能需要,設(shè)計并剪裁出具有特殊功能的處于納米尺度的新材料。這些具有獨特性能的納米材料,在信息、能源、化工、環(huán)境、醫(yī)藥、國防及社會安全領(lǐng)域都有著廣泛的應(yīng)用前景,同時也為物理,化學(xué),生命等基礎(chǔ)學(xué)科的研究與發(fā)展帶來巨大的機(jī)遇。結(jié)晶性和晶體學(xué)取向是材料的兩個很重要的結(jié)構(gòu)特性,對它們的研究可以拓展貴金屬等納米材料的潛在應(yīng)用。本文首先介紹了納米材料的性質(zhì)和應(yīng)用,以及場發(fā)射的概念,接著簡單介紹了納米材料的制備方法和表征方法。最后主要討論了沉積電壓、溫度、納米線直徑對納米線結(jié)晶性和晶體學(xué)取向的影響。通過使用無氰的環(huán)保電解液,采用模板輔助的電化學(xué)沉積法制備出了結(jié)晶性和晶體學(xué)取向可控的金納米線。并分析了沉積電壓、沉積溫度和納米線直徑對這兩個結(jié)構(gòu)特性的影響機(jī)制。并進(jìn)一步研究了金納米線陣列的場發(fā)射效應(yīng)。本文研究發(fā)現(xiàn):低的電壓有助于單晶的生長,而溫度對納米線的結(jié)晶性有著雙重影響,在單晶和多晶納米線中扮演著不同的角色。在單晶生長過程中,溫度場的存在促進(jìn)了生長面上原子的擴(kuò)散;多晶生長過程中,溫度場的存在使生長速率顯著提高,促進(jìn)三維成核。電壓的不同會導(dǎo)致納米線擇優(yōu)取向的不同,這主要是高的電壓引起H離子的吸附導(dǎo)致不同晶面的晶面能發(fā)生變化。具體表現(xiàn)為:高電壓時具有[100]取向,低電壓時具有[111]取向。在保持其他條件不變的情況下,不同直徑的納米線具有不同的擇優(yōu)取向,這個主要是不同直徑的納米線在生長的過程中,兩種不同的界面所占的主導(dǎo)地位不同所引起的。具體表現(xiàn)為:小直徑時,納米線具有[111]取向,大直徑時具有[100]取向。此外還發(fā)現(xiàn),金納米線陣列可以有效促進(jìn)場發(fā)射,單晶納米線頂部的脊?fàn)罱Y(jié)構(gòu)和非密排面的低功函數(shù)是可能的兩個因素。
[Abstract]:Due to the great development and promotion of electronic components and mechanical miniaturization, more and more attention has been paid to the basic research of nanomaterials. When the size of materials is reduced to nanometer size (about 100nm), their physical and chemical properties and even biological activities become very strange due to the quantum size effect. Based on controllable preparation, structure and properties of materials, people are eager to design and cut new nanoscale materials with special functions according to the needs of environment and performance. These nanomaterials with unique properties have a wide range of applications in the fields of information, energy, chemicals, environment, medicine, national defense and social security, as well as in physics, chemistry, The research and development of life and other basic disciplines bring great opportunities. Crystallization and crystallographic orientation are two important structural properties of materials. Their research can expand the potential applications of nanomaterials such as precious metals. In this paper, the properties and applications of nanomaterials and the concept of field emission are introduced. Then, the preparation and characterization of nanomaterials are briefly introduced. Finally, the effects of deposition voltage, temperature and diameter of nanowires on the crystallinity and crystallographic orientation of nanowires are discussed. By using cyanide-free environmental electrolyte and template assisted electrochemical deposition, the crystal and crystallographic orientation of the nanowires were controlled. The influence mechanism of deposition voltage, deposition temperature and nanowire diameter on these two structural characteristics was analyzed. Furthermore, the field emission effect of the Jinnanian wire array is studied. It is found that low voltage contributes to the growth of single crystal, while temperature has a double effect on the crystallinity of nanowires and plays a different role in single crystal and polycrystalline nanowires. In the process of single crystal growth, the existence of temperature field promotes the diffusion of atoms on the growth surface, and in the process of polycrystalline growth, the temperature field increases the growth rate and promotes three-dimensional nucleation. The difference of voltage will lead to different preferred orientation of nanowires, which is mainly due to the adsorption of H ions by high voltage, which leads to the change of crystal energy of different faces. The results show that there are [100] orientation at high voltage and [111] orientation at low voltage. The preferred orientation of nanowires with different diameters is different when other conditions remain unchanged. This is mainly due to the different dominant position of two different interfaces in the growth process of nanowires with different diameters. The results show that the nanowires have [111] orientation at small diameters and [100] orientations at large diameters. It is also found that the gold nanowire array can effectively promote the field emission. The ridge structure at the top of the single crystal nanowires and the low power function of the non-compact surface are two possible factors.
【學(xué)位授予單位】：中國科學(xué)院研究生院（近代物理研究所）
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2015
【分類號】：TB383.1;O614.123

【參考文獻(xiàn)】

相關(guān)期刊論文 前9條

1 彭書賦;孫友梅;羅捷;常海龍;劉杰;侯明東;段敬來;姚會軍;莫丹;張苓;尹經(jīng)敏;陳艷峰;翟鵬飛;曹殿亮;;25MeV/u Kr輻照下PET薄膜的損傷機(jī)制研究[J];原子核物理評論;2010年01期

2 魏方芳;;納米材料的研究及應(yīng)用[J];化學(xué)工程與裝備;2007年03期

3 段敬來,劉杰,朱智勇,王志光,孫友梅,侯明東,金運(yùn)范,姚會軍,宋銀,趙志明,姚存峰;電導(dǎo)法研究紫外光預(yù)輻照對核孔膜徑跡蝕刻的影響[J];核技術(shù);2005年09期

4 李道華,喻永紅;納米材料的合成技術(shù)及其研究進(jìn)展[J];西昌學(xué)院學(xué)報(人文社會科學(xué)版);2004年01期

5 王瑛,朱智勇,孫友梅,金運(yùn)范,王志光,侯明東,段敬來;22MeV/u的Fe離子在PET膜中引起的輻照效應(yīng)研究[J];原子核物理評論;2004年01期

6 王天赤,路嬪,車丕智,辛顯雙,周百斌;納米材料的特性及其在催化領(lǐng)域的應(yīng)用[J];哈爾濱商業(yè)大學(xué)學(xué)報(自然科學(xué)版);2003年04期

7 范景蓮,徐浩翔,黃伯云,劉軍,馬運(yùn)柱;金屬-Al_2O_3陶瓷基復(fù)合材料的研究現(xiàn)狀及應(yīng)用前景[J];粉末冶金材料科學(xué)與工程;2002年03期

8 劉昌龍,朱智勇,金運(yùn)范,王衍斌,孫友梅,侯明東,王志光,劉杰,陳曉曦,張崇宏;35MeV/uAr離子輻照聚酯膜引起的效應(yīng)研究[J];原子核物理評論;2000年04期

9 朱敏;何海龍;馬立超;;納米材料在反艦導(dǎo)彈隱身設(shè)計中的應(yīng)用[J];海軍航空工程學(xué)院學(xué)報;2004年01期

，

本文編號：2356291