基于Mie理论的典型材料纳米结构非局域特性和非线性特性研究

发布时间：2018-04-26 05:26

本文选题：金属纳米结构 + 非局域特性　；参考：《安徽大学》2017年硕士论文

【摘要】：随着科学技术的不断发展,各种小尺寸物体的电磁特性得到了越来越深入的研究。本文研究的纳米结构材料,由于其不同于大尺寸材料的特殊性质,成为当下研究的热点之一。纳米材料是指在三维空间中至少有一维处于纳米尺度范围(1-100nm)或由它们作为基本单元构成的材料,这大约相当于10-100个原子紧密排列在一起的尺度。纳米材料有天然材料和人工材料,随着生成技术的不断发展,纳米级金属颗粒的制作和研究也进一步深入。由于纳米材料的尺寸已经接近电子的相干长度,它的性质因为强相干所带来的自组织使得性质发生很大变化,例如熔点、磁性、光学、导热、导电特性等等,往往不同于该物质在整体状态时所表现的性质。当物质的尺寸小到一定程度时,就不能只用传统理论的观点来描述它的行为。本文基于Mie氏理论以解析解的形式研究了金属纳米结构的非局域(nonlocal)特性及其非线性(nonlinear)特性。其中以Drude模型和非局域流体动力学模型为基础研究了金属纳米线、金属纳米球以及金属纳米管的非局域特性,推导出其消光截面的解析式。进一步研究了在不同尺寸下,其对周围介质的非局域特性;以非谐振振子模型为基础研究了金属纳米球的非线性特性,推导出其非线性情况下的电场表达式,将非线性场用一系列的球矢量波函数展开,进一步研究了其远场特性及极化度。由于纳米结构的非局域特性和非线性特性使其对周围介质具有较高的敏感度,因此纳米结构材料可以被设计成探测传感器用来感测物质的物理化学性质。本文的研究可以为设计一种新型的纳米探测器作为参考。本文的主要工作有:1.充分调研并了解了目前国内外金属纳米结构非局域特性及非线性特性的发展现状,介绍了非局域特性及非线性特性的研究背景,阐明本文所做工作的重要性。2.阐述了研究金属纳米结构非局域特性及非线性特性所用的Mie氏理论及用到的Drude模型、非局域流体动力学模型和非谐振振子模型。3.研究了不同尺寸金属纳米线、球及不同内外半径比金属纳米管的非局域特性,给出了其消光截面的解析解,并比较了不同情况下金属纳米管对周围介质的灵敏度。4.研究了金属纳米球的非线性特性,给出了其在在一次谐波、二次谐波、三次谐波情况下电场的解析式,并进一步研究了其远场特性及极化度。
[Abstract]:With the development of science and technology, the electromagnetic characteristics of various small-sized objects have been studied more and more deeply. The nanostructured materials studied in this paper have become one of the research hotspots because of their special properties different from large-sized materials. Nanomaterials are materials that have at least one dimension in the nanoscale range of 1-100nm in three-dimensional space or are composed of them as basic units, which is equivalent to the scale of 10-100 atoms closely arranged together. There are natural and artificial materials in nanomaterials. With the development of generation technology, the preparation and research of nanocrystalline metal particles are further studied. Because the size of nanomaterials is close to the coherent length of electrons, the properties of nanomaterials have changed greatly because of the self-organization brought about by strong coherence, such as melting point, magnetism, optics, heat conduction, conductivity and so on. It is often different from the nature of the substance in its overall state. When matter is small enough, its behavior cannot be described by conventional theory alone. In this paper, the nonlocal nonlinearity and nonlinear nonlinearity of metal nanostructures are studied in the form of analytical solutions based on Mie's theory. The nonlocal properties of metal nanowires, metal nanospheres and metal nanotubes are studied on the basis of Drude model and non-local hydrodynamic model, and the analytical formula of extinction cross section is derived. The nonlocal properties of the metal nanospheres with different sizes are further studied, and the nonlinear properties of the metal nanospheres are studied based on the nonresonant oscillator model, and the electric field expression under the nonlinear condition is derived. The nonlinear field is expanded by a series of spherical vector wave functions, and its far-field characteristics and polarization are further studied. Because the nonlocal and nonlinear properties of nanostructures make them highly sensitive to the surrounding media, nanostructured materials can be designed to detect the physical and chemical properties of substances by sensors. The research in this paper can be used as a reference for the design of a new nanometer detector. The main work of this paper is: 1. The development status of nonlocal and nonlinear characteristics of metal nanostructures at home and abroad is fully investigated. The research background of nonlocal and nonlinear characteristics is introduced, and the importance of the work done in this paper is clarified. The Mie's theory and Drude model, nonlocal hydrodynamic model and nonresonant oscillator model used to study the nonlocal and nonlinear properties of metal nanostructures are described. The nonlocal properties of metal nanowires, spheres and metal nanotubes with different ratios of inner and outer radii are studied. The analytical solution of extinction cross section is given, and the sensitivity of metal nanotubes to surrounding media under different conditions is compared. The nonlinear characteristics of metal nanospheres are studied, and the analytical expressions of electric field in the case of first harmonic, second harmonic and third harmonic are given, and the far field characteristics and polarization of metal nanospheres are further studied.
【学位授予单位】：安徽大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TB383.1

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