Bifurcations of spatiotemporal stripe patterns formed by Ag/Sb co-electrodeposition
Bifurcations of spatiotemporal stripe patterns formed by Ag/Sb co-electrodeposition
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DOI：
10.1016/s0378-4371(03)00480-1
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发表时间：
2003-09
影响因子：
3.3
通讯作者：
Y. Nagamine;M. Hara
中科院分区：
文献类型：
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作者：
Y. Nagamine;M. Hara
研究了Ag/Sb共沉积金属电极上的各种时空模式，这些模式与反应扩散系统中的模式相似。为了阐明这些时空图案的特性，我们研究了几种传播条纹图案对电流密度的依赖性，使用光学显微镜。根据实验结果，绘制了几种传播条纹图案随电流密度变化的相图。此外，我们发现在电沉积过程的初始阶段，在一个电极上发生了两种不同条纹图案的分叉。两个分叉图案的组合根据电流密度而变化。然而，每个图案对于其可以出现在电极表面上的所有电流密度维持其固有的条纹波长值。图案的固有条纹波长显示一个或两个数量级的波长差异。单轴传播条纹图的条纹速度的固有值也观察到有一个顺序的差异。然而，计算的频率fp（即，条纹速度/条纹波长）几乎相同。最后，在初始阶段的两个分叉模式被统一成一个模式，具有较长的波长随时间，独立于它们的频率。这一特征与反应扩散系统的Belousov-Zhabotinsky（BZ）反应中的模式有很大不同。与BZ反应体系的显著差异清楚地表明，该体系是一个新的体系，应区别于常规体系。
Various spatiotemporal patterns, which are similar to those in reaction–diffusion systems, are studied on metal electrodes formed by Ag/Sb co-electrodeposition. To elucidate the characteristics of these spatiotemporal patterns, we investigated the dependence of several kinds of propagating stripe patterns on the current density, using an optical microscope. Based on the experimental results, a phase diagram of several kinds of propagating stripe patterns against current density was completed. In addition, we discovered that the bifurcations to two different stripe patterns occurred on one electrode at the initial stage of the electrodeposition process. The combination of the two bifurcated patterns changes depending on the current density. However, each pattern sustains its inherent value of the stripe wavelength for all current densities at which it could emerge on an electrode surface. The inherent stripe wavelengths of patterns show a difference in wavelength of one or two orders. The inherent values of stripe velocities of uniaxially propagating stripe patterns were also observed to have a one order difference. However, the calculated frequencies fp(i.e., stripe velocity/stripe wavelength) of uniaxially propagating stripe patterns were found to be nearly the same. Finally, two bifurcated patterns at the initial stage are unified into one pattern with a longer wavelength with time, independently of their frequencies. This characteristic is significantly different from that of patterns in Belousov–Zhabotinsky (BZ) reaction exemplifying the reaction–diffusion system. The marked difference from the BZ reaction system clearly indicates that this system is a new system that should be distinguished from the conventional system.