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题名	团簇壳层结构和尺寸诊断研究
作者	刘丙辰
学位类别	硕士
答辩日期	2000
授予单位	中国科学院上海光学精密机械研究所
导师	倪国权
关键词	团簇 电子壳层 尺寸效应 飞行时间质谱 瑞利散射
中文摘要	团簇是物质存在的一种重要形态，由原子或分子凝聚而成，具有与宏观物体不同的性质。团簇的量子态随尺寸变演变，这导致它奇异的电、光和磁特性。本文涉及金属铝团簇、非金属碳团簇、金属非金属钛－碳和铝－碳混合团簇以及惰性气体团簇等广泛内容。团簇的制备有多种途径，铝团簇、碳团簇和钛－碳混合团簇可用固体材料生成，在本文实验中，用激光蒸发结合高压脉冲载气的技术制备这几种气相团簇。并用飞行时间质谱仪探测团簇负离子，获得团簇相对强度分布谱，从中可得出团簇多项性质的综合信息。在许多金属团簇中电子壳层的作用往往是决定性的，而几何结构也会对团簇的性质有影响作用，在非金属团簇中则更为重要。本文从电子壳层和几何结构两个方面入手解释铝团簇负离子质谱，验证了铝团簇中电子壳层的存在。碳团簇具有多变的几何结构，导致多样的性质，通过对碳负离子质谱的分析，结合实验条件对结果的影响，对不同尺寸范围内的碳团簇结构进行了讨论。实验获得了钛－碳混合团簇的负离子质谱，清晰展示单个碳原子可分辨的团簇分布尺寸范围大大超过了已见报道的同类质谱，在较大尺寸范围内提示了钛－碳混合团簇随尺寸演变的规律。惰性气体团簇由超声膨胀源产生，为探测产生的团簇的尺寸，采用了Rayleigh散射的方法，利用散射截面一尺寸的关系，通过探测散射光的信号推知团簇的尺寸。
英文摘要	Clusters are an important state of matter, consisting of aggregates of atoms and molecules that are small enough not to have the same properties as the bulk liquid or solid. Quantum states in clusters are size-dependent, leading to new electronic, optical, and magnetic properties. The contents involved in this thesis cover aluminum clusters, aluminum-carbon clusters, carbon clusters, titanium-carbon mixed clusters, and rare gas clusters. Aluminum clusters, carbon cluster, and titanium-carbon mixed clusters were produced in a laser vaporization/molecular beam cluster source. Cluster anions are detected by a time of flight mass spectrometer. In some metal clusters, electronic shells are critical to their properties. Meanwhile, the structures of atoms in clusters also affect the properties of clusters, which are more important in nonmetal clusters. The mass spectra obtained of aluminum cluster anions are explained by their electronic and atomic structures. On the other hand, because of many possible types of structures of carbon clusters, mass spectra of carbon cluster anions often show different characters. Through studying the mass spectra of carbon cluster anions under different experimental conditions, the possible structures of carbon clusters in different size ranges are discussed. The mass spectra of titanium-carbon mixed cluster anions shown clearly in a size range far beyond that of any other mass spectra of this kind ever reported are considered to be helpful in our understanding of the structure evolution of metal-carbon mixed clusters. The average sizes of rare gas clusters generated in a supersonic expansion source were measured through a Rayleigh scattering method. Since the scattering cross section of a cluster is a function of its size, the average size of clusters can then be determined through detecting the intensity of the scattered light.
语种	中文
内容类型	学位论文
源URL	[http://ir.siom.ac.cn/handle/181231/16554]
专题	上海光学精密机械研究所_学位论文
推荐引用方式 GB/T 7714	刘丙辰. 团簇壳层结构和尺寸诊断研究[D]. 中国科学院上海光学精密机械研究所. 2000.

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