黄铜铬酸表面膜的导电性

The Electrical Properties of Surface Film Formed on Brass in Chromic Acid

采用金属膜金属结构测量了黄铜在铬酸中形成的表面膜的导电性．实验得到膜的导电性良好，虽为半导体，却表现出准金属行为这一与文献报导不同的结论．分析了膜的成分，建立了金属半导体膜金属（ＭＳＭ）的能带模型，证明了这一结构存在背对背Ｓｃｈｏｔｋｙ二极管．定性分析表明，膜导电性良好，且具有准金属行为的原因是膜中大量杂质及缺陷所致．

Electrical measurements were carried out on surface film formed on brass in chromic acid with the film sandwiched between two metallic electrodes. The results show that the film has a high electrical conductivity,it belongs to a semi conductor,but behaves as a quasi metallic conduct. These results are different from the ones reported before in literature. The composition of the film was analysed,an energy band model for the metal film metal structure was established and two back to back schottky diodes were proved to exist in the structure. Qualitative analyses indicate that such different electrical properties are due to heavy defects and impurities in the film.