摘要
本文报道采用XPS,紫外可见和红外漫反射光谱等表面分析技术,对由方波脉冲电流迭加直流从草酸镀液体系电沉积形成的粉红色和浅绿色铬膜层的结构和组成进行表征.XPS分析结果表明,这些铬膜层由交界层(含Cr_2O_3、Cr和Ni)、中间层(主要成分是Cr_2O_3,也含一定量的水)和表面层(含Cr(Ⅵ)、Cr(Ⅲ)等品种)所组成.铬膜层的颜色和性质主要是由中间层决定的.结晶水和游离水的存在修改了中心离子Cr(Ⅲ)的配位体场,使得彩虹色铬膜层的吸收谱带受到影响.
The structures and constituents of both electrodeposited pink and light-green chromium films from oxalic acid with spuare pulsating current superposed direct current are characterized by means of XPS, UV and IR diffuse reflection spectroscopies. The XPS analysis shows that these chromium films consist of three layers, i. e., interracial layer (Cr_2O_3, Cr and Ni), intermediate layer (Cr_2O_3, also containing some water) ang surface layer (Cr(Ⅵ), Cr(Ⅲ)). The color and properties of the films are mainly determined by the intermediate layer. The presence of hydrate water and free-water modifies the ligand field of central ion Cr(Ⅲ), so that the absorption bands of iridescent chromium films are influenced.
