彩虹色铬膜电沉积研究

Studies on Iridescent Chromium Films Electrodeposition

本文对电沉积铬形成的彩虹色铬膜进行了XPS、UPS分析,并用电化学方法研究其形成过程,根据彩虹色铬膜的成分分布。该膜可分为表面层、中间层和与基底连接的交界层,对彩虹色铬膜的形成机理和显色原因也进行了探讨。

Iridescent chromium films prepared by cathode electrodeposition on Ni substrate are studied by XPS and UPS. The mechanism of the film formation is also studied by electrochemical method. The results show that the films consist of three layers: (1) Surface layer, about 30 nm thick, containing Cr(Ⅵ) and Cr(Ⅲ)[Cr(OH)3, CrOOH and Cr2O3], which were formed by adsorption of chemical compounds near the elecctrode; (2) Intermediate layer, about 200 nm thick, mainly composed of Cr2O3 produced by electroreduction of CrO3; (3) Interfacial layer connected with the substrate, about 150 nm thick, comprised of Cr2O3, Cr and Ni. The third was formed by reduction of the oxide films on the electrode. The colour of the films arises from the absorption of light of the unpaired 3d electrons under the influence of O2- distorted octahedral iigand field and from the light interference in the thin films.