Direct observation of Pt nanocrystal coalescence induced by electron-excitation-enhanced van der Waals interactions
Direct observation of Pt nanocrystal coalescence induced by electron-excitation-enhanced van der Waals interactions
复制标题
电子激发增强范德华相互作用诱导的 Pt 纳米晶体聚结的直接观察
DOI：
10.1007/s12274-013-0396-5
复制
发表时间：
2014-03-01
期刊：
影响因子：
9.9
通讯作者：
Zhang, Ze
中科院分区：
文献类型：
--
作者：
Jiang, Ying;Wang, Yong;Zhang, Ze
在过去的几十年里，纳米晶体聚结在纳米结构制造中引起了极大的关注。随着透射电镜技术的发展，对其机理的研究取得了巨大的进展。然而，许多机制仍然不清楚，特别是缺乏永久偶极矩的纳米晶体站在固体衬底上。在这里，我们报告了在非晶碳衬底上由电子激发增强的范德华相互作用引起的铂纳米晶体的原位发光，通过透射电子显微镜和第一性原理计算研究。发现电子束激发可以显著增强Pt纳米晶体之间的范德华相互作用，降低Pt纳米晶体与碳衬底之间的结合能，两者都促进了聚并。这项工作扩展了我们对在透射电子显微镜下观察到的纳米晶体聚结的理解，并为实际电子束控制纳米制造的潜在途径提供了线索。
Nanocrystal coalescence has attracted paramount attention in nanostructure fabrication in the past decades. Tremendous endeavor and progress have been made in understanding its mechanisms, benefiting from the development of transmission electron microscopy. However, many mechanisms still remain unclear, especially for nanocrystals that lack a permanent dipole moment standing on a solid substrate. Here, we report anin situcoalescence of Pt nanocrystals on an amorphous carbon substrate induced by electron-excitationenhanced van der Waals interactions studied by transmission electron microscopy and first principles calculations. It is found that the electron-beam-induced excitation can significantly enhance the van der Waals interaction between Pt nanocrystals and reduce the binding energy between Pt nanocrystals and the carbon substrate, both of which promote the coalescence. This work extends our understanding of the nanocrystal coalescence observed in a transmission electron microscope and sheds light on a potential pathway toward practical electronbeam-controlled nanofabrication.