RUI: EAM/Simulation Studies of the Energetics and Kinetics of Surface Reconstruction

本科院校研究补助金用于表面重建的理论研究。表面重构是指发生在某些材料表面原子层中的原子的自发重排。这些重排令人感兴趣，因为它们代表了比较表面能量学理论处理和表面层结构实验探针的重要机会。重建表面比静态表面提供更严格的科学方法测试。我们将研究两个具体的系统。将研究金的（110）表面，其中通过表面扩散形成具有缺失金行的重建表面。嵌入原子法和蒙特卡罗技术将用于研究能量学。钨的（001）表面，其中每个原子以交替模式从其平衡位置略微位移，也将被研究。在这种情况下，将研究与表面相图有关的能量学。由于表面层之外没有其他原子，固体表面上原子的集体性质与块体中的原子不同。因此，表面原子的能量学与体中的原子不同。这种能量学差异的结果之一是，表面原子的排列方式与本体不同。这些重新排列的原子可以导致表面层具有与大块固体不同的物理性质。例如，某些表面结构比其他表面结构更有利于催化。提出的研究将研究两种模型系统中的两类表面重建。这些结果将有助于理解为什么在这些材料中形成特定的表面结构。

This Research at Undergraduate Institution grant is awarded for theoretical research on surface reconstruction. Surface reconstruction refers to the spontaneous rearrangement of atoms that occurs in the surface atomic layers of some materials. These rearrangements are of interest sine they represent important opportunities to compare theoretical treatments of surface energetics and experimental probes of the structure of surface layers. Reconstructive surfaces present much more stringent tests of scientific methods than do static surfaces. Two specific systems will be investigated. The (110) surface of gold will be studied where through surface diffusion a reconstructed surface with missing rows of gold is formed. The Embedded Atom Method and Monte Carlo techniques will be used to study the energetics. The (001) surface of tungsten in which each atom is displaced slightly from its equilibrium position in an alternating pattern will also be studied. In this case the energetics related to the surface phase diagram will be examined. %%% The collective properties of atoms on the surfaces of solids are different than those in the bulk due to the absence of other atoms beyond the surface layer. The energetics of surface atoms are thus different than those in the bulk. One of the consequences of this difference in energetics is that the surface atoms can arrange themselves differently than the bulk. These rearranged atoms can result in the surface layer having different physical properties than the bulk solid. For instance, certain surface structures are better than others for catalysis. The proposed research will study two classes of surface reconstruction in two model systems. The results will help to understand why specific surface structures are formed in these materials.