Atomically controlled electrochemical nucleation at superionic solid electrolyte surfaces
Atomically controlled electrochemical nucleation at superionic solid electrolyte surfaces
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DOI：
10.1038/nmat3307
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发表时间：
2012-06-01
期刊：
影响因子：
41.2
通讯作者：
Waser, Rainer
中科院分区：
文献类型：
--
作者：
Valov, Ilia;Sapezanskaia, Ina;Waser, Rainer
在原子尺度上，电化学平衡以及质量和电荷通过界面的传递对于微观理解基本物理化学过程具有重要意义。接近原子尺寸、相位不稳定性和仪器限制限制了分辨率。在这里，我们展示了RbAg4I5超离子导体薄膜表面电化学银相形成过程中最终的横向、质量和电荷分辨率。我们发现，固体电解质中少量的电子供体使扫描隧道显微镜测量和原子分辨成像成为可能。我们证明Ag临界核的形成是速率限制的。这个过程的吉布斯能取离散值，临界原子核的原子数在很大范围内保持恒定。我们的方法对于阐明原子开关的机制至关重要，并强调了将这种方法扩展到各种其他电化学系统的可能性。
Electrochemical equilibrium and the transfer of mass and charge through interfaces at the atomic scale are of fundamental importance for the microscopic understanding of elementary physicochemical processes. Approaching atomic dimensions, phase instabilities and instrumentation limits restrict the resolution. Here we show an ultimate lateral, mass and charge resolution during electrochemical Ag phase formation at the surface of RbAg4I5 superionic conductor thin films. We found that a small amount of electron donors in the solid electrolyte enables scanning tunnelling microscope measurements and atomically resolved imaging. We demonstrate that Ag critical nucleus formation is rate limiting. The Gibbs energy of this process takes discrete values and the number of atoms of the critical nucleus remains constant over a large range of applied potentials. Our approach is crucial to elucidate the mechanism of atomic switches and highlights the possibility of extending this method to a variety of other electrochemical systems.