In this paper, the effect of the atom ratio and interface structure on the surface evolution of Janus Cu–Ag Nanoparticles (NPs) were studied by molecular dynamics (MDs) simulation during sintering process. The results show that Cu/Ag alloys tend to form the Cu-core@Ag-shell NPs with stable configuration in the case of excessive Ag. However, the different arrangements of atoms and interface lead to Janus Cu–Ag NPs exhibiting unique coalescence during the contact stage of sintering process, and the interface with Cu/Ag two-type atoms is more likely to diffuse. Moreover, the systems gradually change from separate NPs to a uniform Cu/Ag alloy as the temperature rising, meanwhile the shrinkage ratio of the Janus Cu–Ag NPs is stable at 80%.

中文翻译：

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Janus Cu-Ag 纳米粒子的表面演化：原子排列和界面结构的影响

本文通过分子动力学（MDs）模拟研究了烧结过程中原子比和界面结构对Janus Cu-Ag纳米粒子（NPs）表面演化的影响。结果表明，在过量Ag的情况下，Cu/Ag合金倾向于形成具有稳定构型的Cu-core@Ag-shell NPs。然而，不同的原子和界面排列导致Janus Cu-Ag NPs在烧结过程的接触阶段表现出独特的聚结，与Cu/Ag两种原子的界面更容易扩散。此外，随着温度的升高，体系逐渐从单独的纳米粒子转变为均匀的铜/银合金，同时两面铜-银纳米粒子的收缩率稳定在 80%。