金属纳米团簇结构失稳的加速分子动力学研究

Metallic nanoclusters are functional materials with a wide prospect of applications owing to their unique physical and chemical properties. Since their performances rely heavily on the morphology and structure, the investigation on their stabilities and the mechanism of instability is of great scientific significance to their design, synthesis, and final usage. By employing the parallel trajectory splicing (ParSplice) based accelerated molecular dynamics method and related experiments, this project tends to systematically study the structural instability of metallic nanoclusters and the associated physical mechanisms. The goal of this project is to present a clear description of the experimentally observed dynamic processes occurring at the temperatures much lower than the melting points and meanwhile with durations in the timescale of microseconds and above. The obtained results can break through the current bottleneck in the relevant research caused by the relatively short timescales and thus solve the existing controversy. Both monometallic and bimetallic nanoclusters will be considered in this project. Their microstructure evolutions and dynamic behaviors will be examined by the energy and structure analysis. Especially, the reconstruction of surface or interface, lattice structure change, and atomic diffusion will be explored. Ascertaining these problems could lead to atomic-level understandings of the intrinsic physical mechanism of the structural instability. This project is expected to provide a scientific basis for the further design and preparation of the metallic functional nanomaterials with both excellent performance and good stability.

金属纳米团簇具有独特的物理与化学性质，是应用前景广阔的功能材料。由于其性能与形貌结构直接相关，因此，研究它们的稳定性与失稳机制对其设计、合成和应用具有重要的科学意义。本项目拟采用基于并行轨迹拼接的加速分子动力学方法并结合相关实验，针对金属纳米团簇的结构失稳现象及物理机制进行系统的研究，希望对实验中远离熔点温区的时间尺度为微秒量级以上的结构失稳过程给出清晰的动力学描述，从而突破当前同类研究中由时间尺度较小而造成的瓶颈，澄清现有争论。本项目以单金属与双金属纳米团簇为研究对象，拟通过对系统的总能、原子的格位能量等能量学分析，以及原子排列的结构学分析，探讨其失稳过程中的微结构演化与微观动力学行为，重点关注其中的表面或界面重构、晶格结构改变与原子扩散，进而从原子层次上对结构失稳的本征物理机制作出诠释。预期通过对以上内容的研究，为设计和制备具有高性能与良好稳定性的金属纳米功能材料提供科学依据。

金属纳米团簇具有独特的物理与化学性质，是应用前景广阔的功能材料。由于其性能与形貌结构直接相关，因此，研究它们的稳定性与失稳机制对其设计、合成和应用具有重要的科学意义。本项目采用基于并行轨迹拼接的加速分子动力学方法，针对金属纳米团簇的结构失稳现象及物理机制进行了系统的研究，给出了其失稳过程的清晰的动力学描述。本项目以单金属与双金属纳米团簇为研究对象，通过对系统的总能、原子的格位能量等能量学分析，以及原子排列的结构学分析，探讨了其失稳过程中的微结构演化与微观动力学行为，重点关注了其中的表面（界面）重构、晶格结构改变与原子扩散，进而从原子层次上对结构失稳的本征物理机制作出了诠释。本项目的研究结果为设计和制备具有高性能与良好稳定性的金属纳米功能材料提供了科学依据。