期刊
PHYSICAL REVIEW LETTERS
卷 111, 期 12, 页码 -出版社
AMER PHYSICAL SOC
DOI: 10.1103/PhysRevLett.111.128302
关键词
-
资金
- NSF-AGS Postdoctoral Research Fellowship
- CA League of Food Processors
- Directorate For Geosciences
- Div Atmospheric & Geospace Sciences [1137701] Funding Source: National Science Foundation
Colloids are known to form planar, hexagonal closed packed (hcp) crystals near electrodes in response to electrohydrodynamic (EHD) flow. Previous work has established that the EHD velocity increases as the applied ac frequency decreases. Here we report the existence of an order-to-disorder transition at sufficiently low frequencies, despite the increase in the attractive EHD driving force. At large frequencies (similar to 500 Hz), spherical micron-scale particles form hcp crystals; as the frequency is decreased below similar to 250 Hz, however, the crystalline structure transitions to randomly closed packed (rcp). The transition is reversible and second order with respect to frequency, and independent measurements of the EHD aggregation rate confirm that the EHD driving force is indeed higher at the lower frequencies. We present evidence that the transition is instead caused by an increased particle diffusivity due to increased particle height over the electrode at lower frequencies, and we demonstrate that the hcp-rcp transition facilitates rapid annealing of polycrystalline domains.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据