Abstract

An approach is proposed to perform a mathematical description of the electrochemical formation and growth of binary alloy nuclei on the surface of an indifferent electrode under constant supersaturation (overpotential). This approach considers the total flux of two species of deposited ions in the electrolyte bulk to the surface of hemispherical new-phase nuclei. The concentration profile is averaged with allowance for the mole fraction ratio of the components. The cases of instantaneous and progressive nucleation with diffusion-controlled growth are studied. The overlap of the diffusion zones of the nuclei is analyzed in terms of the Scharifker–Hills model. Equations are derived to calculate the apparent diffusion coefficient of deposited ions, the number of nuclei per unit electrode surface, and the steady-state nucleation rate.

中文翻译：

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定电条件下二元合金核的成核和扩散控制生长模型

摘要

提出了一种方法，用于在恒定过饱和（超电势）下，对无差异电极表面上二元合金核的电化学形成和生长进行数学描述。该方法考虑了电解质中两种沉积离子到半球形新相核表面的总通量。浓度分布取各组分的摩尔分数比的平均值。研究了具有扩散控制的生长的瞬时和渐进成核的情况。根据Scharifker-Hills模型分析了原子核扩散区的重叠。得出方程式以计算沉积离子的表观扩散系数，每单位电极表面的核数和稳态成核率。