少层旋转石墨烯的热传导及多终端石墨烯的热整流效应

发布时间：2018-03-11 00:30

本文选题：热输运　切入点：分子动力学方法　出处：《湘潭大学》2017年硕士论文　论文类型：学位论文

【摘要】：石墨烯由于其优异的电学、力学和热学性质,成为了近年来最受关注的材料之一,在各个领域都有巨大的应用前景。同时低维纳米材料热输运的研究逐渐成为目前凝聚态物理的前沿课题。石墨烯是目前已知的材料中热导率最高的材料,在热传导、热管理和热能利用中都有着重要的价值。本文对旋转石墨烯的热输运性质以及多终端石墨烯的热整流现象进行了研究,得到的结果为制备基于石墨烯的纳米热器件提供了物理模型和理论依据。本论文总共分为五章,首先在第一章我们主要介绍了本文的选题背景以及研究目的。第二章我们主要对基于牛顿力学的经典分子动力学方法进行了介绍和公式推导。本文我们采用非平衡分子动力学方法来计算石墨烯的热输运性质。第三章我们利用分子动力学方法研究了不同旋转角度下多层石墨烯的层间和面内的热输运现象。研究结果表明,石墨烯的层间传热和面内传热受旋转角度的影响较大,并且旋转30°时层间耦合最低,相比于正常AB堆垛能产生较大隔热效果。而且在石墨烯逐渐向块体过渡的时候这种变化更明显。第四章我们利用分子动力学方法计算了多终端石墨烯的热整流现象。研究结果表明,多终端石墨烯跟两终端石墨烯的热整流现象有很大的不同,我们可以通过调节控制端的温度进而改变热整流效率。第五章我们对本论文的工作做了一个总结,并对低维纳米材料热输运的研究做了简要的展望。
[Abstract]:Graphene has become one of the most attractive materials in recent years because of its excellent electrical, mechanical and thermal properties. At the same time, the study of thermal transport of low-dimensional nanomaterials has gradually become a frontier topic in condensed matter physics. Graphene is the material with the highest thermal conductivity in the field of heat conduction. Thermal management and thermal energy utilization are of great value. In this paper, the thermal transport properties of rotatory graphene and the phenomenon of thermal rectification of multi-terminal graphene are studied. The obtained results provide a physical model and theoretical basis for the fabrication of graphene based nano-thermal devices. In the first chapter, we mainly introduce the background and purpose of this thesis. In the second chapter, we introduce the classical molecular dynamics method based on Newtonian mechanics and deduce the formula. In chapter 3, we use molecular dynamics method to study the interlaminar and in-plane thermal transport of multilayer graphene at different rotation angles. The interlaminar heat transfer and in-plane heat transfer of graphene are greatly affected by rotation angle, and the coupling between layers is the lowest at 30 掳rotation. Compared with the normal AB stacking, the heat insulation effect is larger, and the change is more obvious when graphene is gradually transitioning to the block. In Chapter 4th, we calculate the thermal rectification of multi-terminal graphene by molecular dynamics method. The results of the study show that. The thermal rectifying phenomenon of multi-terminal graphene is very different from that of two terminal graphene. We can change the efficiency of thermal rectifier by adjusting the temperature of the control terminal. In Chapter 5th, we make a summary of the work in this paper. The research on thermal transport of low-dimensional nanomaterials is briefly prospected.
【学位授予单位】：湘潭大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O613.71

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