Metal nanoparticle arrays are excellent candidates for a variety of applications due to the versatility of their morphology and structure at the nanoscale. Bottom-up self-assembly of metal nanoparticles provides an important complementary alternative to the traditional top-down lithography method and makes it possible to assemble structures with higher-order complexity, for example, nanospheres, nanocubes, and core–shell nanostructures. Here we present a mechanism study of the self-assembly process of 1-D noble metal nanoparticles arrays, composed of Au, Ag, and AuAg alloy nanoparticles. These are prepared within an encapsulated germanium nanowire, obtained by the oxidation of a metal–germanium nanowire hybrid structure. The resulting structure is a 1-D array of equidistant metal nanoparticles with the same diameter, the so-called nanobead (NB) array structure. Atom-probe tomography and transmission electron microscopy were utilized to investigate the details of the morphological and chemical evolution during the oxidation of the encapsulated metal–germanium nanowire hybrid-structures. The self-assembly of nanoparticles relies on the formation of a metal–germanium liquid alloy and the migration of the liquid alloy into the nanowire, followed by dewetting of the liquid during shape-confined oxidation where the liquid column breaks-up into nanoparticles due to the Plateau–Rayleigh instability. Our results demonstrate that the encapsulating oxide layer serves as a structural scaffold, retaining the overall shape during the eutectic liquid formation and demonstrates the relationship between the oxide mechanical properties and the final structural characteristics of the 1-D arrays. The mechanistic details revealed here provide a versatile tool-box for the bottom-up fabrication of 1-D arrays nanopatterning that can be modified for multiple applications according to the RedOx properties of the material system components.

中文翻译：

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封装的纳米线内的一维金属纳米珠阵列通过红牛诱导的去湿：原子探针层析成像的机理研究

金属纳米颗粒阵列由于其在纳米级的形态和结构的多功能性而成为各种应用的极佳候选者。金属纳米粒子的自下而上的自组装为传统的自上而下的光刻方法提供了重要的补充选择，并使组装具有更高阶复杂性的结构成为可能，例如，纳米球，纳米立方体和核-壳纳米结构。在这里，我们介绍了由Au，Ag和AuAg合金纳米粒子组成的一维贵金属纳米粒子阵列自组装过程的机理研究。这些是在封装的锗纳米线中制备的，该锗纳米线是通过金属-锗纳米线杂化结构的氧化获得的。得到的结构是具有相同直径的等距金属纳米粒子的一维阵列，所谓的纳米珠（NB）阵列结构。利用原子探针层析成像和透射电子显微镜研究了被封装的金属-锗纳米线杂化结构的氧化过程中形态和化学演化的细节。纳米粒子的自组装依赖于金属-锗液态合金的形成以及液态合金向纳米线中的迁移，然后在形状受限的氧化过程中对液体进行脱湿，其中液柱由于以下原因分解成纳米颗粒高原-瑞利不稳定性。我们的结果表明，封装氧化物层可作为结构支架，在共晶液体形成过程中保持整体形状，并证明了氧化物力学性能与一维阵列最终结构特征之间的关系。这里揭示的机械细节提供了一种用于自底向上制造一维阵列纳米图案的多功能工具箱，可以根据材料系统组件的RedOx属性对其进行修改以用于多种应用。