Direct observation of Pt nanocrystal coalescence induced by electron-excitation-enhanced van der Waals interactions
Pt nanocrystals, coalescence, electron excitation, van der Waals interactions
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 an in situ coalescence 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.
Tsinghua University Press
Ying Jiang,Yong Wang,Yu Yang Zhang,Zhengfei Zhang,Wentao Yuan,Chenghua Sun,Xiao Wei,Casey N. Brodsky,Chia-Kuang Tsung,Jixue Li,Xiaofeng Zhang,Scott X. Mao,Shengbai Zhang,Ze Zhang, Direct observation of Pt nanocrystal coalescence induced by electron-excitation-enhanced van der Waals interactions. NanoRes.2014, 7(3): 308–314