Cu-Ni雙金屬納米團(tuán)簇結(jié)構(gòu)與性質(zhì)的多尺度模擬
發(fā)布時(shí)間：2018-07-21 20:33
【摘要】：雙金屬納米團(tuán)簇在最近幾十年來受到了人們廣泛的關(guān)注,它具有更為優(yōu)良的性能與純的金屬納米團(tuán)簇相比。因?yàn)殡p金屬納米團(tuán)簇具有特殊的物理和化學(xué)上的性質(zhì),所以能夠被運(yùn)用于化工、能源等眾多的領(lǐng)域。由于組成雙金屬納米團(tuán)簇的兩種原子本身的各項(xiàng)性質(zhì)不一樣,在組成的雙金屬納米團(tuán)簇體系會(huì)呈現(xiàn)出多樣的變化,這些變化可能擁有一項(xiàng)特殊的能力,正是因?yàn)檫@些特殊結(jié)構(gòu)吸引了很多人的目光,對(duì)雙金屬納米團(tuán)簇進(jìn)行研究具有很重要的實(shí)際意義。本論文主要是通過計(jì)算研究不同尺度的Cu-Ni雙金屬納米團(tuán)簇并分析其結(jié)構(gòu)和性能,采用的方法有蒙特卡洛模擬(Monte Carlo, MC)、VASP軟件、CP2K軟件。在結(jié)果分析后得出了如下結(jié)論：1.對(duì)于大體系和小體系的Cu-Ni雙金屬納米團(tuán)簇都進(jìn)行細(xì)致的分析,不論是通過MC計(jì)算得到的還是通過CP2K計(jì)算得到的Cu-Ni雙金屬納米團(tuán)簇都滿足Cu原子優(yōu)先占據(jù)結(jié)構(gòu)的外層位置隨著Cu原子含量的增加,首先是頂點(diǎn)位,其次是邊位,在次是表面位,最后是內(nèi)部位置,比較特殊地,對(duì)于大體系的正二十面體結(jié)構(gòu)Cu原子占據(jù)中心位置要優(yōu)先于邊位,對(duì)于小體系的正二十面體結(jié)構(gòu)Cu原子占據(jù)中心位置由于表面位。2.使用本課題組自主編寫的新型原子對(duì)分布函數(shù)的軟件(Atomic Pair Distribution Function for Bimetallic Clusters, APDFBC)計(jì)算出大體系Cu-Ni雙金屬納米團(tuán)簇的新型原子對(duì)分布函數(shù)并分析第一近鄰原子距離并與實(shí)驗(yàn)數(shù)據(jù)進(jìn)行對(duì)比。3.對(duì)于大體系的Cu-Ni雙金屬納米團(tuán)簇,我們還用bop軟件計(jì)算其序參數(shù)去分析局部結(jié)構(gòu),反映出Cu-Ni雙金屬納米團(tuán)簇在800K和1200K下是液相,100K和300K下是固相,500K下是固液相共存。4.用VASP軟件計(jì)算了CuxNin-x(n=54,55)雙金屬納米團(tuán)簇的性質(zhì),發(fā)現(xiàn)結(jié)構(gòu)的對(duì)稱性會(huì)影響體系的磁矩,通過分析體系總的態(tài)密度(dos)圖和單個(gè)金屬s,p和d軌道的態(tài)密度圖中的聯(lián)系。體系的磁性主要是由Ni原子提供,無磁性的Cu原子在體系內(nèi)部的相互作用下會(huì)表現(xiàn)出一定的磁性。
[Abstract]:Bimetallic nanoclusters have attracted much attention in recent decades and have better performance than pure metal nanoclusters. Because bimetallic nanoclusters have special physical and chemical properties, they can be used in many fields such as chemical industry, energy and so on. Because the properties of the two atoms that make up the bimetallic nanoclusters are different, the composition of the bimetallic nanoclusters presents a variety of changes, which may have a particular ability. It is precisely because these special structures have attracted a lot of attention that it is of great practical significance to study bimetallic nanoclusters. In this paper, the structure and properties of Cu-Ni bimetallic nanoclusters with different scales are studied by means of calculation and analysis. The methods used are Monte Carlo simulation (MC) VASP software and CP2K software. After analyzing the results, the following conclusion is drawn: 1. The Cu-Ni bimetallic nanoclusters in both large and small systems are analyzed in detail. The Cu-Ni bimetallic nanoclusters obtained by MC calculation or CP2K calculation all satisfy the Cu atom preferentially occupying the outer layer of the structure with the increase of Cu atom content, the first is the vertex position, the second is the edge position, and the next is the surface position. Finally, the inner position, especially, the central position of the icosahedron structure Cu atom is superior to the edge position for the large system, and for the small system, the surface position of the icosahedron structure Cu atom occupies the center position because of the surface position. The new atomic pair distribution function of Cu-Ni bimetallic clusters has been calculated by Atomic pair Distribution function for (APDFBC), and the first nearest neighbor atomic distance has been analyzed and compared with the experimental data. For Cu-Ni bimetallic nanoclusters in large scale systems, the order parameters of Cu-Ni bimetallic nanoclusters are calculated by bop software to analyze the local structure. It is shown that Cu-Ni bimetallic nanoclusters are liquid-phase at 800K and 1200K and solid-liquid coexisting at 300K at 500K. The properties of CuxNin-x bimetallic nanoclusters are calculated by using vspp software. It is found that the symmetry of the structure affects the magnetic moment of the system. The relationship between the total density of states (dos) diagram of the system and the density of states of single metal sp and d orbitals is analyzed. The magnetic properties of the system are mainly provided by Ni atoms, and the non-magnetic Cu atoms exhibit certain magnetic properties under the interaction within the system.
【學(xué)位授予單位】：北京化工大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2015
【分類號(hào)】：TB383.1
本文編號(hào)：2136777
[Abstract]:Bimetallic nanoclusters have attracted much attention in recent decades and have better performance than pure metal nanoclusters. Because bimetallic nanoclusters have special physical and chemical properties, they can be used in many fields such as chemical industry, energy and so on. Because the properties of the two atoms that make up the bimetallic nanoclusters are different, the composition of the bimetallic nanoclusters presents a variety of changes, which may have a particular ability. It is precisely because these special structures have attracted a lot of attention that it is of great practical significance to study bimetallic nanoclusters. In this paper, the structure and properties of Cu-Ni bimetallic nanoclusters with different scales are studied by means of calculation and analysis. The methods used are Monte Carlo simulation (MC) VASP software and CP2K software. After analyzing the results, the following conclusion is drawn: 1. The Cu-Ni bimetallic nanoclusters in both large and small systems are analyzed in detail. The Cu-Ni bimetallic nanoclusters obtained by MC calculation or CP2K calculation all satisfy the Cu atom preferentially occupying the outer layer of the structure with the increase of Cu atom content, the first is the vertex position, the second is the edge position, and the next is the surface position. Finally, the inner position, especially, the central position of the icosahedron structure Cu atom is superior to the edge position for the large system, and for the small system, the surface position of the icosahedron structure Cu atom occupies the center position because of the surface position. The new atomic pair distribution function of Cu-Ni bimetallic clusters has been calculated by Atomic pair Distribution function for (APDFBC), and the first nearest neighbor atomic distance has been analyzed and compared with the experimental data. For Cu-Ni bimetallic nanoclusters in large scale systems, the order parameters of Cu-Ni bimetallic nanoclusters are calculated by bop software to analyze the local structure. It is shown that Cu-Ni bimetallic nanoclusters are liquid-phase at 800K and 1200K and solid-liquid coexisting at 300K at 500K. The properties of CuxNin-x bimetallic nanoclusters are calculated by using vspp software. It is found that the symmetry of the structure affects the magnetic moment of the system. The relationship between the total density of states (dos) diagram of the system and the density of states of single metal sp and d orbitals is analyzed. The magnetic properties of the system are mainly provided by Ni atoms, and the non-magnetic Cu atoms exhibit certain magnetic properties under the interaction within the system.
【學(xué)位授予單位】：北京化工大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2015
【分類號(hào)】：TB383.1
【參考文獻(xiàn)】
相關(guān)期刊論文 前2條
1 ;Direct Electrodeposition of Cu-Ni-W Alloys for the Liners for Shaped Charges[J];Journal of Materials Science & Technology;2010年05期
2 蔣治良,劉紹璞,陳颯;銀原子團(tuán)簇的共振散射光譜研究[J];貴金屬;2001年03期
，本文編號(hào)：2136777
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