Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, USA.
Department of Physics, Korea University, Seoul 136-701, Republic of Korea.
Nat Nanotechnol. 2015 Apr;10(4):345-52. doi: 10.1038/nnano.2015.23. Epub 2015 Mar 9.
The Plateau-Rayleigh instability was first proposed in the mid-1800s to describe how a column of water breaks apart into droplets to lower its surface tension. This instability was later generalized to account for the constant volume rearrangement of various one-dimensional liquid and solid materials. Here, we report a growth phenomenon that is unique to one-dimensional materials and exploits the underlying physics of the Plateau-Rayleigh instability. We term the phenomenon Plateau-Rayleigh crystal growth and demonstrate that it can be used to grow periodic shells on one-dimensional substrates. Specifically, we show that for certain conditions, depositing Si onto uniform-diameter Si cores, Ge onto Ge cores and Ge onto Si cores can generate diameter-modulated core-shell nanowires. Rational control of deposition conditions enables tuning of distinct morphological features, including diameter-modulation periodicity and amplitude and cross-sectional anisotropy. Our results suggest that surface energy reductions drive the formation of periodic shells, and that variation in kinetic terms and crystal facet energetics provide the means for tunability.
高原-瑞利不稳定性最初在 19 世纪中期被提出，用于描述水柱如何分裂成液滴以降低其表面张力。后来，这种不稳定性被推广到各种一维液体和固体材料的恒容重新排列。在这里，我们报告了一种独特的一维材料生长现象，利用了高原-瑞利不稳定性的基础物理原理。我们将这种现象称为高原-瑞利晶体生长，并证明它可以用于在一维基底上生长周期性壳层。具体来说，我们表明，在某些条件下，将 Si 沉积到均匀直径的 Si 核上、Ge 沉积到 Ge 核上以及 Ge 沉积到 Si 核上，可以生成直径调制的核壳纳米线。通过合理控制沉积条件，可以调节不同的形态特征，包括直径调制的周期性、幅度和横截面各向异性。我们的结果表明，表面能的降低驱动了周期性壳层的形成，而动力学项和晶体面能的变化为可调性提供了手段。
