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arXiv · 2002.07009

Restructuring and Breakup of Nanowires with the Diamond Cubic Crystal Structure into Nanoparticles

Vyacheslav N. Gorshkov·Vladimir V. Tereshchuk·Pooya Sareh2
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Abstract

A kinetic Monte Carlo approach is applied to study physical mechanisms responsible for the breakup of nanowires with the diamond cubic crystal structure into a chain of nanoparticles discovered in preceding experiments on Silicon nanowires. We show that this process is based on the well-known mechanism of roughening transition, which specifically manifests itself in quasi-one-dimensional systems/nanowires with a pronounced anisotropy of the surface energy density. Depending on the temperature and orientation of the nanowire relative to its internal crystal structure, the wavelengths of substantial cross-sectional modulations exceed its initial radius by 4 to 18 times. For certain orientations, a straight nanowire at the initial stage of evolution forms a serpentine/helical structure. The scenarios of the stage of nanowire ruptures into single nanoclusters are also diverse: either each spindle-shaped region of the nanowire transforms into a separate drop (by long-wave surface perturbations), or the adjacent short-scale beads absorb each other due to the Ostwald ripening effect, which can be accompanied by the formation of long-lived many-body dumbbells. The discovered features of the dynamics of quasi-onedimensional systems expand our conceptions of the physical mechanisms involved in the breakup of nanowires (presented by Nichols and Mullins as a classical model for such instabilities) which could be useful in applications based on chains of ordered nanoparticles.

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Vyacheslav N. Gorshkov, Vladimir V. Tereshchuk, Pooya Sareh2. 2020-02-12. Restructuring and Breakup of Nanowires with the Diamond Cubic Crystal Structure into Nanoparticles. https://doi.org/10.1016/j.mtcomm.2019.100727

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