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arXiv · 1607.01494

Fluid-like Surface Layer and Its Flow Characteristics in Glassy Nanotubes

Matthew C. Wingert·Soonshin Kwon·Shengqiang Cai·Renkun Chen
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Abstract

We observed strongly size-dependent viscoelasticity in amorphous SiO2 and Si nanotubes with shell thickness down to ~8 nm. A core-shell model shows that a ~1 nm thick fluid-like surface layer has a significant effect on the mechanical behavior of nanotubes and matches well with our experimental results. Surprising, the surface layer exhibits a room temperature viscosity equivalent to that of bulk glass above 1000 C. Additionally, a low activation energy extracted from temperature dependent creep tests indicates that the viscous flow in the surface layer is due to bond motion/switching, instead of bond breaking. These findings unambiguously show the presence of a fluid-like surface layer and elucidate its role on dynamic mechanical behavior in nanoscale inorganic glass.

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Matthew C. Wingert, Soonshin Kwon, Shengqiang Cai, Renkun Chen. 2016-07-06. Fluid-like Surface Layer and Its Flow Characteristics in Glassy Nanotubes. https://doi.org/10.1021/acs.nanolett.6b03377

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