A New Characteristic Length Scale on Surfaces

该奖项的目的是通过建立其存在，其对加工条件的依赖性及其对表面形态的影响来研究新特征长度尺度的概念。晶体纳米棒的直径约为100 nm，许多表面特征具有相似的尺寸。有趣的是，这个尺寸的起源仍然未知，而纳米棒的制造已经成为一种常规做法。这个项目的重点是这个维度的起源。假设这个维度是由多层包围的表面原子岛的特征。为了证实这一假设，该研究采用基于密度泛函理论的从头计算，经典分子力学模拟和晶格动力学蒙特卡罗模拟，并采取简单的金属Cu和Au作为原型材料。如果成功的话，新的表面特征长度尺度的概念将代表表面科学的一个新补充。除了对科学界的好处外，该奖项的成功还将提供一种控制表面粗糙度或表面形态的新方法。例如，了解完整的表面特征长度尺度将使基于科学的设计的阅读头的硬盘驱动器，晶体纳米棒，和催化剂的可持续能源应用。该奖项还将为本科生和研究生提供教育机会，包括在这种情况下代表性不足的少数民族研究生。

The objective of this award is to investigate the concept of new characteristic length scale by establishing its existence, its dependence on processing conditions, and its effects on surface morphologies. Crystalline nanorods are on the order of 100 nm in diameter, and many surface features have similar dimension. It is interesting to note that the origin of this dimension remains unknown while nanorods fabrication has become a routine practice. This project focuses on the very origin of this dimension. The hypothesis is that this dimension is characteristic of surface atomic islands that are bounded by multiple layers. Aiming to confirm this hypothesis, the proposed research uses density-functional-theory based ab initio calculations, classical molecular mechanics simulations, and lattice kinetic Monte Carlo simulations; and takes simple metals Cu and Au as the prototype materials. If successful, the established concept of new characteristic length scale on surfaces will represent a new addition to surface science. In addition to the benefit to scientific communities, the success of this award will also provide a new means of controlling surface roughness, or surface morphology in general. For example, understanding the complete set of surface characteristic length scales will enable science-based design of reading head of hard disk drives, that of crystalline nanorods, and that of catalysts for sustainable energy applications. The award will also provide an opportunity for the education of undergraduate and graduate students, including an underrepresented minority graduate student in this case.