Computer Simulations of Thin Films and Interfaces

该奖项由先进材料和加工计划颁发，并得到化学和材料研究部的支持。几种计算机模拟技术将被应用于研究金属薄膜的形成和性质。这些模拟很好地模拟了实验室通过原子沉积形成非晶态和有序薄膜的过程。为了更好地了解薄膜的稳定性和弹性性质，将分别对金属系统中的固-液和固-固界面进行模拟。原子相互作用由嵌入的原子方法类型的相互作用势来描述，该相互作用势将再现来自广泛的凝聚相实验的数据。系统的微观结构分析将被用来表征非晶态薄膜的短程有序性、有序薄膜中的缺陷、可控参数对薄膜形态的影响以及界面结构相关性的衰减。模拟中产生的微观模型将用于研究薄膜的二能级系统、振动模式和弹性性质。并与实验数据作了比较：(1)非晶态铜-锆膜中的二能级体系和振动模；(2)铂薄膜的低温层状生长。对金属薄膜生长、表面形态和表面-液体界面的计算机模拟将澄清特定实验的结果，在某些情况下将提供对不直接服从于实验的微观事件的洞察。

This award is made in the Advanced Materials and Processing Initiative and is supported by both the Chemistry and Materials Research Divisions. Several computer simulation techniques will be applied to study the formation and properties of thin metallic films. The simulations closely mimic the laboratory formation of both amorphous and ordered thin films by atom deposition. Solid-liquid and solid-solid interfaces in metallic systems will be simulated separately to gain a better understanding of stability and elastic properties of thin films. The atomic interactions are described by the Embedded Atom Method-type interaction potentials that will reproduce data from a wide range of condensed phase experiments. A systematic analysis of the microscopic structure will be used to characterize short-range order in amorphous films, defects in ordered films, the effect of controllable parameters on film morphology, and the decay of structural correlations at interfaces. The microscopic models generated in the simulations will be used to study two-level systems, vibrational modes and elastic properties of the films. Comparison will be made with experimental data on (1) two-level systems and vibrational modes in amorphous copper-zirconium films and, (2) layer-by-layer growth of platinum films at low temperature. %%% Computer simulations of metallic film growth, surface morphology and surface-liquid interfaces will clarify the results of specific experiments and in some cases will provide insights into microscopic events not directly amenable to experiment.