First-principle analysis on coupling of mechanical and electrical properties in interface region

电子器件和微或纳米机电系统（MEMS/NEMS）需要各种材料。因此，其中存在许多界面，界面上的材料具有特征性质。在本研究中，我们首先利用第一性原理分子动力学模拟（伪势，平面波基础）研究了铝在（100）表面硅衬底上的沉积过程。当调光器在硅表面形成时，我们研究了两种类型的界面结构。(1)第一层上的铝原子在较暗的排之间形成平行线(2)垂直排列的排。第一层上的铝原子具有广泛的电子分布。铝原子之间的键比铝原子与硅之间的键更强。碳纳米管作为先进器件或MEMS/NEMS的元件，以其优异的机电性能而受到研究人员的关注。由于它们与其他部件相连，因此变形发生在靠近界面的管中。然后，我们对碳纳米管的力学和电子性能的耦合进行了二次研究，以探索由于约束而导致的界面附近行为的变化。我们通过紧密结合模拟径向和轴向载荷。方法。根据手性的不同，在没有外部负载的情况下，这些管表现出金属或半导体的性质。研究表明，这些性能会因外载荷引起的变形而改变。

Electronic devices and micro-or nano-electromechanical systems (MEMS/NEMS) require various materials. Thus, there exists many interfaces in then and the material on the interface possesses characteristic property. At first in this study, we have investigated the process of aluminum deposition on silicon substrate with a (100) surface by using the first-principle molecular dynamics simulation (pseudo-potential, basis of plane wave). As the rows of dimmers are formed on the silicon surfaces, we examined two types of the interface structures.(1)The aluminum atoms on the first layer form parallel line between dimmer rows(2)Those align perpendicular to it.The aluminum atoms on the first layer possess broad distribution of electrons. The bond between the aluminum atoms is stronger than that between the aluminum atom and the silicon at the interface.The carbon nano-tubes are getting researcher's attentions because of its excellent mechanical/electronic properties as components in advanced device or MEMS/NEMS. Since they are connected with other components, the deformation takes place in the tube near the interface. Then, we secondary investigated the coupling of mechanical and electronic properties of carbon nano-tubes in order to explore the change in the behavior near the interface due to the constraint. We simulate the radial and axial load by the tight binding. method. Depending on the chirality, the tubes show metallic or semi-conducting properties under no external load. This study reveals that these properties are changed by the deformation due to the external load.