FLINAK-Na_2SiF_6熔盐体系中Si的电结晶机理  

Study on Electrocrystallization Mechanism of Silicon in Molten Salts

作　　者：李运刚[1] 蔡宗英[2] 翟玉春[1] 唐国章[2] 

机构地区：[1]东北大学材料冶金学院,沈阳110004 [2]河北理工学院冶金工程系,河北唐山063009

出　　处：《有色金属》2005年第2期66-68,87,共4页Nonferrous Metals

基　　金：河北省自然科学基金资助项目(502263)

摘　　要：在FLINAK-Na2SiF6熔盐体系中,以Pt为参比电极、硅钢片为工作电极、石墨为辅助电极,在750℃的温度下,用循环伏安法和计时安培法对硅的电结晶过程进行研究。结果表明,该熔盐体系中硅的电沉积经历了晶核形成过程,并需要一定的过电位,其电结晶按连续成核和三维生长方式进行,晶体生长速度常数k’的对数值与阶跃电位基本呈线性关系,并随阶跃电位的负移而增大,外加电位对Si晶体生长具有显著的影响。The electro-crystallization mechanism of silicon is investigated in FLINAK-Na_2SiF_6 system by cyclic voltammetry and chronoamperometry at 750℃ with Pt as reference electrode, silicon sheet as working electrode and graphite as auxiliary electrode. It is showed by the results that the over potential is required in the nucleating process of silicon and the electro-crystallization follows the mechanism of progressive nucleation and three-dimension growth process. The constant k′ of crystal growth rate is linearly increased with the negative movement of step potential. There are obviously influences of step potential on the growth of Si crystal.

关 键 词：熔盐体系 Na2SiF6 电结晶机理 晶体生长 计时安培法 循环伏安法 参比电极 工作电极 辅助电极 结晶过程 形成过程 生长方式 线性关系 速度常数 硅钢片 过电位 电沉积 阶跃 石墨 

分 类 号：TQ171.733[化学工程—玻璃工业] TF821.032[化学工程—硅酸盐工业]