Computer simulation of heterogeneous nucleation and crystal growth in metallic alloys

用蒙特卡罗(MC)和分子动力学(MD)模拟技术研究了单组分和二元金属系统中的异相形核和晶体生长。通过研究固液界面的各种性质、生长动力学、熔体的传输性质、成核势垒和成核率，检验相场和相场晶体方法、密度泛函理论(DFT)和经典成核理论。对不同结构衬底上的晶核进行MD模拟，可以阐明晶核的结构，特别是对于二元体系，缺陷在生长过程中的作用。后一次运行的起始构型是由MC模拟结合伞形抽样提供的；这些MC模拟也用于确定成核势垒和研究临界核的结构。

Monte Carlo (MC) and Molecular Dynamics (MD) simulation techniques are used to investigate heterogeneous nucleation and crystal growth in one-component and binary metallic systems. Phase-field as well as phase-field crystal approaches, density functional theory (DFT) and classical nucleation theory shall be tested by studying various properties of solid-liquid interfaces, growth kinetics, transport properties of the melt, nucleation barriers and nucleation rates. MD simulation of crystalline nuclei on different structured substrates allows to elucidate the structure of the nuclei and, in particular for binary systems, the role of defects during growth. The starting configurations for the latter runs are provided by MC simulations in conjunction with umbrella sampling; these MC simulations are also used to determine nucleation barriers and to study the structure of critical nuclei.