铜电极表面铜锡合金电结晶机理

Abstract

在弱酸性柠檬酸盐体系铜锡合金镀液中,采用线性扫描伏安(lSV)、循环伏安(CV)和计时安培实验方法,运用SCHArIfkEr-HIllS(SH)理论模型和HEErMAn-TArAllO(HT)理论模型分析拟合实验结果,研究铜锡合金在铜电极上的电沉积过程与电结晶机理.结果表明,铜锡合金在铜电极表面实现共沉积并遵循扩散控制下三维瞬时成核的电结晶过程.电位阶跃从-0.80 V负移至-0.85 V(VS SCE),HT理论分析得到铜锡合金的成核与生长的动力学参数分别为成核速率常数(A)值从20.19 S-1增加至177.67 S-1,成核活性位点密度数(n0)从6.10x105CM-2提高至1.42x106CM-2,扩散系数(d)为(6.13±0.62)x10-6CM2S-1.

The co-deposition and electrocrystallization of Cu-Sn alloy in a weak acidic citrate bath were studied by linear sweep voltammetry(LSV), cyclic voltammetry(CV), and chronoamperometry.The Scharifker- Hill(SH) theory model and Heerman- Tarallo(HT) theory model were applied to analyze the chronoam- perometry data.The results show that the Cu-Sn alloy co-deposited on copper electrode, following instan- taneous nucleation with three-dimensional(3D) growth under diffusion control.The kinetic parameters were obtained using the HT model.As the step potential shifted from-0.80 to-0.85 V, the nucleation rate constant(A) increased from 20.19 to 177.67 s-1, the density of active nucleation sites(N0) increased from 6.10×105to 1.42×106cm-2, and the diffusion coefficient(D) was(6.13±0.62)×10 6cm2 s-1.