Based on Monte Carlo (MC) simulations of the interaction of energetic noble gas ions with carbon nanostructures, we have derived the ion-deposited energy formulas and their applications for the above interaction. We also have studied the nuclear point mass effects i.e. the well-known mass ratio effects, and the nuclear point charge effects on the ion-deposited energy then the damage regularities. In particular, we, for first time, find a straight line of the penetrating point threshold energies for energetic noble gas ions. Near this straight line, the nuclear point charge effects dominate the ion-deposited energy then the damage regularities.
Strong spatial confinement and highly reduced dielectric screening provide monolayer transition metal dichalcogenides (TMDCs) with strong many-body effects, thereby possessing optically forbidden excitonic states (i.e., dark excitons) at room temperature. Herein, we explore the interaction of surface plasmons with dark excitons in hybrid systems consisting of stacked gold nanotriangles (AuNTs) and monolayer WS2. We observe a narrow Fano resonance when the hybrid system is surrounded by water, and we attribute the narrowing of the spectral Fano linewidth to the plasmon-enhanced decay of dark K-…
We present a first-principles study of the surface magnetism induced by Cr, Mn, Fe and Co adatoms on the (111) surfaces of Rh, Pd, Ag, Ir, Pt and Au. We first describe how the different contributions to the surface magnetism enter the magnetic stray field, with special attention paid to the induced orbital moments. Then we present results for the spin and orbital magnetic moments of the adatoms, and for the induced surface spin and orbital magnetic moments, the latter being further divided into atomic and inter-atomic contributions. We investigate how the surface magnetism is determined by the…
Self-Assembled Nanostructure Formation in Chemical Vapor Deposition
当通过化学气相沉积在衬底上生长薄膜时，第一沉积层的演变可以在介观尺度上通过反应扩散型动力学模型来描述。对于单原子层，这样的模型描述的原子覆盖的演变，由于代表吸附-脱附和化学过程和非线性扩散项的Cahn-Hilliard型的反应项的组合效应。在低于临界温度时，这种组合可能导致均匀沉积层的不稳定性。这种不稳定性触发了对应于基底覆盖的规则空间变化的纳米结构的形成。模式、波长和对称性是由动力学变量而不是变分变元选择的。根据反应和扩散诱导的非线性之间的平衡，可以获得一系列的自组装结构，包括六边形阵列的点，条和各种类型的局部结构。这些结构可以启动不同类型的生长机制，包括Volmer-Weber和Frank-Van der Merwe类型的生长。不同类型的沉积单层的研究，这种方法的相关性进行了讨论。
Efficient detection of the magnetic state at nanoscale dimensions is an important step to utilize spin logic devices for computing. Magnetoresistance effects have been hitherto used in magnetic state detection, but they suffer from energetically unfavorable scaling and do not generate an electromotive force that can be used to drive a circuit element for logic device applications. Here, we experimentally show that a favorable miniaturization law is possible via the use of spin-Hall detection of the in-plane magnetic state of a magnet. This scaling law allows us to obtain a giant signal by spin…
In two-dimensional van der Waals (vdWs) materials, the relative twist angle between adjacent layers not only controls their electronic properties, but also determines their stacking energy. This effect makes it much easier to realize energetically favorable configurations of the vdWs materials, for example, Bernal-stacked structure of bilayer graphene. Here we demonstrate that we can controllably tailor adhesive energy landscape of graphene nanostructures on graphene and stabilize the system with tunable twist angle by using a one-dimensional tilt grain boundary (GB). The area ratio with diffe…
Carbon nanowall (CNW) is a two dimensional graphitic nanostructures with many potential applications like field emission, catalyst support for fuel cell and negative electrode for batteries. CNWs were grown here on Si substrates by plasma enhanced chemical vapor deposition using N2/CH4 plasma at 6500C temperature. Deposited CNWs were characterized by scanning electron microscopy and Raman spectroscopy. Results obtained by Raman spectroscopic techniques are extensively studied. It shows existence of D, G, D/, G/, and D+D/ bands. These bands are analyzed to obtain detail structural information a…
