石墨烯微谐振器动力学分析

发布时间：2018-09-14 17:03

【摘要】：自2004年诞生以来,石墨烯以其优异的性质激发了人们的强烈的兴趣。石墨烯是用来制作纳米器件的理想材料,近些年关于石墨烯在纳米器件的研究越来越广泛,而基于石墨烯的微谐振器因其质量轻、体积小和机械共振频率高等优点在传感器及信号处理等领域有着广泛的应用。本文针对基于石墨烯的微谐振器进行研究,采用分子动力学软件LAMMPS,运用AIREBO势函数对完美及含有缺陷石墨烯结构的力学相关特性进行了仿真和分析。论文主要工作如下:1.介绍了石墨烯的基本特性、石墨烯的制备方法、石墨烯的研究现状以及分子动力学方法的基本概念和主要技术。2.根据石墨烯结构特性,构建了基于石墨烯的微谐振器,初步确定了结构的尺寸参数,并对石墨烯谐振器的谐振频率特性分析。着重分析了在不同应力作用下,石墨烯的谐振频率变化特性。随着外力的增大,石墨烯的谐振频率呈现非单调递增。3.分析温度对石墨烯谐振频率的影响。将仿真温度设置在0.1K至1000K范围之间,当温度小于75K时,石墨烯的谐振频率为99.7GHz;当温度在75K至1000K时,其谐振频率为132.9GHz。分析了不同手性及长宽比对石墨烯谐振特性的影响,分析表明手性对石墨烯的谐振频率影响不大,而石墨烯的不同长宽比尺寸对其谐振频率影响较大。当扶手椅型石墨烯的长宽比约为1.5时,其谐振频率为598GHz,而当扶手椅型石墨烯的长宽比约为10时,其谐振频率为66.4GHz。4.介绍了石墨烯缺陷的定义和类型。分析单原子缺位缺陷和边界缺陷在不同温度下对石墨烯的谐振频率的影响,并将仿真温度设置在0.1K至1000K范围之间。当温度小于75K时,石墨烯的谐振频率为99.3GHz;当温度在75K至1000K时,其谐振频率为132.5GHz。分析不同应力对存在边界缺陷的石墨烯结构的谐振频率及振动特性的变化影响,含有边界缺陷的石墨烯谐振频率增加速度小于完整的石墨烯谐振频率变化速度。
[Abstract]:Since its birth in 2004, graphene has aroused strong interest for its excellent properties. Graphene is an ideal material for the fabrication of nano-devices. In recent years, graphene has been studied more and more widely in nano-devices, and graphene based microresonators are light because of their light mass. The advantages of small size and high resonance frequency are widely used in sensor and signal processing. In this paper, the microresonator based on graphene is studied, and the mechanical properties of perfect and defective graphene structures are simulated and analyzed by using AIREBO potential function using molecular dynamics software LAMMPS,. The main work of this paper is as follows: 1. The basic properties of graphene, the preparation method of graphene, the research status of graphene and the basic concept and main technology of molecular dynamics are introduced. According to the structure characteristics of graphene, the microresonator based on graphene was constructed, the dimension parameters of the structure were preliminarily determined, and the resonance frequency characteristics of graphene resonator were analyzed. The resonant frequency variation characteristics of graphene under different stresses are emphatically analyzed. With the increase of external force, the resonant frequency of graphene increases by. 3. The effect of temperature on the resonance frequency of graphene was analyzed. When the temperature is less than 75K, the resonant frequency of graphene is 99.7GHz, and when the temperature is 75K to 1000K, the resonant frequency of graphene is 132.9 GHz. The effects of chirality and aspect ratio on the resonance frequency of graphene are analyzed. The results show that the chirality has little effect on the resonance frequency of graphene, but the different aspect ratio of graphene has a great effect on the resonant frequency of graphene. When the aspect ratio of the armchair graphene is about 1.5, the resonant frequency is 598 GHz, and when the aspect ratio of the armchair graphene is about 10:00, the resonant frequency is 66.4 GHz. 4. The definition and type of graphene defects are introduced. The effects of monatomic vacancy defects and boundary defects on the resonant frequencies of graphene at different temperatures are analyzed, and the simulation temperature is set between 0.1K and 1000K. The resonance frequency of graphene is 99.3 GHz when the temperature is less than 75K, and 132.5 GHz when the temperature is between 75K and 1000K. The effect of different stresses on the resonant frequency and vibration characteristics of graphene structure with boundary defects is analyzed. The resonant frequency of graphene with boundary defects increases faster than that of complete graphene.
【学位授予单位】：西安电子科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN751.2;O613.71

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