Silver nanoparticles were synthesized using the inert gas aggregation technique. We found the optimal experimental conditions to synthesize nanoparticles at different sizes: 1.3 ± 0.2, 1.7 ± 0.3, 2.5 ± 0.4, 3.7 ± 0.4, 4.5 ± 0.9, and 5.5 ± 0.3 nm. We were able to investigate the dependence of the size of the nanoparticles on the synthesis parameters. Our data suggest that the aggregation of clusters (dimers, trimer, etc.) into the active zone of the nanocluster source is the predominant physical mechanism for the formation of the nanoparticles. Our experiments were carried out in conditions that kept the density of nanoparticles low, and the formation of larges nanoparticles by coalescence processes was avoided. In order to preserve the structural and morphological properties, the impact energy of the clusters landing into the substrate was controlled, such that the acceleration energy of the nanoparticles was around 0.1 eV/atom, assuring a soft landing deposition. High-resolution transmission electron microscopy images showed that the nanoparticles were icosahedral in shape, preferentially oriented with a five-fold axis perpendicular to the substrate surface. Our results show that the synthesis by inert gas aggregation technique is a very promising alternative to produce metal nanoparticles when the control of both size and shape are critical for the development of practical applications.
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机译:使用惰性气体聚集技术合成了银纳米颗粒。我们发现了合成不同尺寸的纳米粒子的最佳实验条件:1.3±0.2、1.7±0.3、2.5±0.4、3.7±0.4、4.5±0.9和5.5±0.3 nm。我们能够研究纳米颗粒大小对合成参数的依赖性。我们的数据表明,簇(二聚体,三聚体等)聚集到纳米簇源的活性区中是形成纳米颗粒的主要物理机制。我们的实验是在保持纳米颗粒密度较低的条件下进行的,避免了通过聚结过程形成大颗粒纳米颗粒的情况。为了保留结构和形态学特性,控制着陆到基体中的团簇的冲击能量,以使纳米粒子的加速能约为0.1 eV /原子,从而确保了软着陆沉积。高分辨率透射电子显微镜图像显示,纳米粒子的形状为二十面体,优先取向为垂直于基材表面的五倍轴。我们的结果表明,当尺寸和形状的控制对于实际应用的开发至关重要时,通过惰性气体聚集技术进行合成是生产金属纳米颗粒的非常有希望的替代方法。
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