碳納米材料與金屬復(fù)合結(jié)構(gòu)中空位缺陷產(chǎn)生和作用機(jī)制的理論研究
發(fā)布時(shí)間：2018-08-09 12:53
【摘要】：從上個(gè)世紀(jì)90年代開始,碳納米材料就成為了很多前沿領(lǐng)域的研究熱點(diǎn),這主要?dú)w功于其獨(dú)特的結(jié)構(gòu)和優(yōu)異的物理、化學(xué)性質(zhì)。碳納米材料主要包括零維的富勒烯、一維的碳納米管和二維材料石墨烯等,由于其獨(dú)特的幾何結(jié)構(gòu)特性,在當(dāng)今新型功能材料、微納電子學(xué)器件等高新領(lǐng)域有著非常廣闊的應(yīng)用前景。例如,在新能源的核電池領(lǐng)域,輻射損傷所致的電池效能和壽命降低一直是一個(gè)棘手的問題,美國研究者Liviu Popa-simil提出了基于碳納米管和金屬復(fù)合材料的核電池設(shè)計(jì)方案,來實(shí)現(xiàn)核能到電能的高效轉(zhuǎn)換(設(shè)計(jì)轉(zhuǎn)化效率高達(dá)50%),其設(shè)計(jì)中就是利用了碳納米管的耐輻照特性。本文的研究工作,就是基于這樣一個(gè)設(shè)計(jì)方案,采用分子動(dòng)力學(xué)方法,進(jìn)一步研究了多壁碳納米管中包覆金屬后,對整體耐輻照性能的影響。同時(shí)又考慮了輻照損傷所產(chǎn)生的單空位缺陷,對石墨烯與金屬的復(fù)合材料的穩(wěn)定性以及其中碳原子和金屬原子結(jié)合強(qiáng)度的影響。首先基于分子動(dòng)力學(xué)的方法,本文通過構(gòu)建三層碳納米管中包覆金屬的模型,并在100eV-1000eV的能量范圍內(nèi),模擬用碳原子轟擊整個(gè)體系,得出了輻照后體系中產(chǎn)生的配位缺陷、完美結(jié)構(gòu)缺陷(perfect structure defect,pst缺陷)[1]和濺射原子的數(shù)目,并統(tǒng)計(jì)了總的輻射損傷量,與同樣體系中,沒有金屬內(nèi)嵌的情況作了對比。結(jié)果表明,在三層碳納米管中內(nèi)嵌金屬銅后,整個(gè)體系的輻射損傷量有明顯降低,從而提高了整體的耐輻照性能,同時(shí)也驗(yàn)證了碳納米管材料在核電池中應(yīng)用的可行性。本文運(yùn)用密度泛函理論,研究了單空位缺陷對石墨烯和金屬復(fù)合材料中碳原子和鎳原子結(jié)合強(qiáng)度的影響機(jī)理,探討了不同位置的缺陷所產(chǎn)生的不同的作用。計(jì)算時(shí),我們選擇了與石墨烯晶格匹配最接近的金屬鎳,使得石墨烯在Ni(111)面上形成1×1的結(jié)構(gòu),構(gòu)建了6層鎳原子和一層石墨烯的4×4的模型。根據(jù)鎳與單層石墨烯結(jié)合的相對位置,我們構(gòu)建了四種不同的結(jié)構(gòu),并分別模擬了在其中引入單空位缺陷后,體系的結(jié)構(gòu)變化,最終發(fā)現(xiàn),缺陷的引入,增強(qiáng)了缺陷趨于的石墨烯層和第一層Ni的結(jié)合,進(jìn)而使得整個(gè)體系更加穩(wěn)定;不同的缺陷位置也有不同的影響,top位的缺陷比hollow位缺陷對二者結(jié)合的加強(qiáng)更加明顯。綜上所述,本論文基于分子動(dòng)力學(xué)的方法,模擬研究了碳原子轟擊碳納米管包覆金屬這個(gè)模型體系,初步獲得了結(jié)構(gòu)缺陷與輻射損傷量的變化關(guān)系。論文通過運(yùn)用密度泛函理論,研究了單空位缺陷對石墨烯和金屬復(fù)合材料中碳原子和鎳原子結(jié)合強(qiáng)度的影響機(jī)理,探討了不同位置缺陷所產(chǎn)生的作用差異性。這些研究結(jié)果可為今后進(jìn)一步開展石墨烯與金屬的界面結(jié)合研究提供一定的理論參考。基于目前的研究工作,未來可開展更加系統(tǒng)性的研究,如研究除銅和鎳之外的金屬原子與石墨烯材料的結(jié)合強(qiáng)度與缺陷的關(guān)系等。
[Abstract]:Since the 90s of last century, carbon nanomaterials have become a hot spot in many frontiers, mainly due to their unique structure and excellent physical and chemical properties. Carbon nanomaterials mainly include zero dimensional fullerenes, one-dimensional carbon nanotubes and two-dimensional material graphene, due to their unique geometric properties, in the case of their unique geometric properties. This new type of functional materials, micro nanoelectronics devices and other high-tech fields have a very broad application prospects. For example, in the field of new energy nuclear batteries, the reduction of battery efficiency and life caused by radiation damage has been a difficult problem. Liviu Popa-simil of the United States proposed nuclear power based on carbon nanotubes and metal composites. The design of the pool is designed to achieve an efficient conversion of nuclear energy to electrical energy (up to 50% of the design conversion efficiency). In its design, the radiation resistance of carbon nanotubes is used in the design. This paper is based on a design scheme, using molecular dynamics method to further study the overall resistance of multi wall carbon nanotubes after the coating of metal. The effects of radiation properties on the single vacancy caused by radiation damage, the stability of the composites of graphene and metal and the influence of the bond strength of carbon atoms and metal atoms are considered. First, based on the method of molecular dynamics, the model of coating metal in three layers of carbon nanotubes is constructed and in 100eV-100 In the energy range of 0eV, the whole system was bombarded with carbon atoms, and the coordination defects produced in the irradiated system, the number of perfect structural defects (perfect structure defect, PST defect) [1] and the sputtering atom were obtained, and the total radiation damage was calculated, and the results were compared with those in the same system, without metal inlay. The radiation damage of the whole system is reduced obviously in the three layer carbon nanotubes, and the radiation resistance of the whole system is improved. At the same time, the feasibility of the application of the carbon nanotube materials in the nuclear battery is also verified. The influence mechanism of the bond strength of the nickel atom is discussed, and the different functions of the defects at different positions are discussed. In the calculation, we choose the closest metal nickel with the graphene lattice, making the graphene formed 1 x 1 Structure on the Ni (111) surface and constructing the 4 * 4 model of the 6 layer nickel atom and the one layer of graphene. In the relative position of the binding, we constructed four different structures, and simulated the structural changes of the system after the introduction of single vacancy defects. Finally, it was found that the introduction of the defects enhanced the binding of the graphene layer and the first layer of Ni, which made the whole system more stable, and different defect positions were different. As a result, the defect of the top bit is more obvious than that of the two. To sum up, based on the method of molecular dynamics, this paper simulated the model system of carbon nanotube cladding metal by carbon atom bombardment, and preliminarily obtained the relationship between the structural defects and the change of radiation damage. The effect of single vacancy on the bonding strength of carbon atoms and nickel atoms in graphene and metal composites is studied. The differences in the effect of defects in different positions are discussed. These results can provide some theoretical reference for further development of the interface of graphene and metal. In the future, more systematic research can be carried out, such as the relationship between the binding strength of metal atoms and Shi Moxi materials except for copper and nickel.
【學(xué)位授予單位】：中國科學(xué)院研究生院(上海應(yīng)用物理研究所)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2016
【分類號】：TB383.1;O613.71
本文編號：2174135
[Abstract]:Since the 90s of last century, carbon nanomaterials have become a hot spot in many frontiers, mainly due to their unique structure and excellent physical and chemical properties. Carbon nanomaterials mainly include zero dimensional fullerenes, one-dimensional carbon nanotubes and two-dimensional material graphene, due to their unique geometric properties, in the case of their unique geometric properties. This new type of functional materials, micro nanoelectronics devices and other high-tech fields have a very broad application prospects. For example, in the field of new energy nuclear batteries, the reduction of battery efficiency and life caused by radiation damage has been a difficult problem. Liviu Popa-simil of the United States proposed nuclear power based on carbon nanotubes and metal composites. The design of the pool is designed to achieve an efficient conversion of nuclear energy to electrical energy (up to 50% of the design conversion efficiency). In its design, the radiation resistance of carbon nanotubes is used in the design. This paper is based on a design scheme, using molecular dynamics method to further study the overall resistance of multi wall carbon nanotubes after the coating of metal. The effects of radiation properties on the single vacancy caused by radiation damage, the stability of the composites of graphene and metal and the influence of the bond strength of carbon atoms and metal atoms are considered. First, based on the method of molecular dynamics, the model of coating metal in three layers of carbon nanotubes is constructed and in 100eV-100 In the energy range of 0eV, the whole system was bombarded with carbon atoms, and the coordination defects produced in the irradiated system, the number of perfect structural defects (perfect structure defect, PST defect) [1] and the sputtering atom were obtained, and the total radiation damage was calculated, and the results were compared with those in the same system, without metal inlay. The radiation damage of the whole system is reduced obviously in the three layer carbon nanotubes, and the radiation resistance of the whole system is improved. At the same time, the feasibility of the application of the carbon nanotube materials in the nuclear battery is also verified. The influence mechanism of the bond strength of the nickel atom is discussed, and the different functions of the defects at different positions are discussed. In the calculation, we choose the closest metal nickel with the graphene lattice, making the graphene formed 1 x 1 Structure on the Ni (111) surface and constructing the 4 * 4 model of the 6 layer nickel atom and the one layer of graphene. In the relative position of the binding, we constructed four different structures, and simulated the structural changes of the system after the introduction of single vacancy defects. Finally, it was found that the introduction of the defects enhanced the binding of the graphene layer and the first layer of Ni, which made the whole system more stable, and different defect positions were different. As a result, the defect of the top bit is more obvious than that of the two. To sum up, based on the method of molecular dynamics, this paper simulated the model system of carbon nanotube cladding metal by carbon atom bombardment, and preliminarily obtained the relationship between the structural defects and the change of radiation damage. The effect of single vacancy on the bonding strength of carbon atoms and nickel atoms in graphene and metal composites is studied. The differences in the effect of defects in different positions are discussed. These results can provide some theoretical reference for further development of the interface of graphene and metal. In the future, more systematic research can be carried out, such as the relationship between the binding strength of metal atoms and Shi Moxi materials except for copper and nickel.
【學(xué)位授予單位】：中國科學(xué)院研究生院(上海應(yīng)用物理研究所)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2016
【分類號】：TB383.1;O613.71
【參考文獻(xiàn)】
相關(guān)期刊論文 前1條
1 宋虎;楊文寧;周曉松;羅順忠;彭汝芳;;富勒烯~(60)Co γ輻照的穩(wěn)定性研究[J];輻射研究與輻射工藝學(xué)報(bào);2011年01期
，本文編號：2174135
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