Long-Term Electrodeposition under a Uniform Parallel Magnetic Field. 1. Instability of Two-Dimensional Nucleation in an Electric Double Layer
Long-Term Electrodeposition under a Uniform Parallel Magnetic Field. 1. Instability of Two-Dimensional Nucleation in an Electric Double Layer
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均匀平行磁场下的长期电沉积。
DOI：
10.1021/acs.jpcb.0c05903
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发表时间：
2020
期刊：
影响因子：
3.3
通讯作者：
Y. Yamauchi & R. Aogaki
中科院分区：
文献类型：
--
作者：
R. Morimoto;M. Miura;A. Sugiyama;M. Miura;Y. Oshikiri;Y. Kim;I. Mogi;S. Takagi;Y. Yamauchi & R. Aogaki
在平行磁场作用下，酸性硫酸铜溶液长期沉积铜后，形成了许多直径为10 ~ 100 μm的枝晶状次生结核。这是一种新型的微磁流体动力学（MHD）效应，是由三维（3D）和二维（2D）原子核通过氢离子的特异性吸附而不稳定生长而产生的（第二次微磁流体动力学效应）。从电沉积的不稳定性来看，虽然扩散层的三维成核始终是不稳定的，但随着氢离子等离子特异性吸附，稳定的二维成核在长期沉积后变得不稳定。三维和二维核的竞争生长产生球形结节作为它们的复合材料，导致它们的枝晶生长。此外，二维成核过程中发生的非平衡波动虽然很小，但会随着洛伦兹力（MHD流）引起的层流溶液流动而迁移。根据离子吸附是特异性的还是非特异性的，行进的不对称波动分别将方向改变为上游或下游。
Under a parallel magnetic field, after long-term copper deposition from an acidic copper sulfate solution, numerous spherical secondary nodules of 10 to 100 μm diameters were formed one upon another in dendritic mode. This is a new type of micro-magnetohydrodynamic (MHD) effect arising from the unstable growth of three-dimensional (3D) and two-dimensional (2D) nuclei by specific adsorption of hydrogen ions (second micro-MHD effect). From the viewpoint of instability in electrodeposition, though 3D nucleation in the diffusion layer is always unstable, with ionic specific adsorption such as hydrogen ions, stable 2D nucleation turns unstable after long-term deposition. The resultant competitive growth of 3D and 2D nuclei produces spherical nodules as their composite, leading to their dendritic growth. Furthermore, though negligibly small, nonequilibrium fluctuations occurring in 2D nucleation migrate with the laminar solution flow caused by Lorentz force (MHD flow). Depending on whether the ionic adsorption is specific or nonspecific, the traveling asymmetrical fluctuation changes the direction to the upstream or downstream side, respectively.