扩散限制和非扩散限制对电沉积银形貌的影响  

Effects of Diffusion Limitation and Non-Diffusion Limitation on the Morphology of Silver by Electrodeposition

作　　者：尤红军[1] 方吉祥[1] 孔鹏[1] 丁秉钧[1] 

机构地区：[1]西安交通大学金属强度与疲劳国家重点实验室,陕西西安710049

出　　处：《稀有金属材料与工程》2008年第6期1042-1045,共4页Rare Metal Materials and Engineering

基　　金：国家自然科学基金资助项目(50471033)

摘　　要：通过外加电压,以硅片为阳极在硝酸银溶液中,将银离子还原成单质银在硅基底表面上沉积生长,在不同外加电压下沉积得到不同形貌的银沉积物。为了解释电压对银沉积形貌的影响,通过对银的电沉积极化曲线进行分析,发现在电沉积过程中,沉积物会受多种动力学的影响,根据不同的动力学因素,极化曲线被分成了3个区域:电化学反应动力学区,扩散限制动力学区,反应和扩散控制竞争的动力学区。通过SEM观察到,银沉积物在这3个区域内会形成不同的形貌,分别为:多面体,分形和枝晶。扩散限制和非扩散限制理论(DLA)被用来对这3种形态的银沉积物产生的原因进行了分析。Silver aggregation was eletrodeposited on silicon plate in silver nitrate aqueous solution and observed by TEM and SEM. It is found that the morphology of silver deposition transform from polyhedron to dendrite structure with the voltage increasing. Different kinetic factors control the different growth processes and can be divided into three kinetic regions according to the polarization curve： the electrochemical reaction; the diffusion limitation; and the competition of reaction and diffusion. In first field, the kinetic of crystal growth controlled the all deposition process. In second field, the kinetic of diffusion limitation controlled the process. The silver precipitates have different morphologies in the three regions according to the SEM observation. This paper analyzes the different deposition processes in the three fields and how the kinetic factor influences the shape.

关 键 词：电沉积 银 极化曲线 扩散限制 枝晶 

分 类 号：TB383.1[一般工业技术—材料科学与工程]