Semiconductor properties and protective role of passive films of iron base alloys
Semiconductor properties and protective role of passive films of iron base alloys
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DOI：
10.1016/j.corsci.2006.05.020
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发表时间：
2007-01-01
影响因子：
8.3
通讯作者：
Tsuchiya, Hiroaki
中科院分区：
文献类型：
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作者：
Fujimoto, Shinji;Tsuchiya, Hiroaki
用光电化学和电化学阻抗谱研究了Fe-18 Cr合金在硼酸盐缓冲溶液（pH = 8.4）和0.1M H2SO 4溶液中形成的钝化膜的半导体性质。光电流显示了两个光作用谱，分别来自外层的氢氧化物和内层的氧化物。一个典型的n型半导体行为观察到的光电流和阻抗的钝化膜中形成的硼酸盐缓冲溶液。另一方面，在硫酸溶液中产生负光电流，其绝对值随着施加的电位的增加而减小。这表明钝化膜表现为p型半导体。而Mott-Schottky曲线显示了典型的n型半导体特性。结果表明，Fe-18 Cr合金在硼酸盐缓冲溶液中形成的钝化膜由n型外层氢氧化物和内层氧化物组成。Fe-18 Cr合金在硫酸中的钝化膜由p型氧化物和n型氢氧化物组成。根据钝化膜的电子结构讨论了钝化膜的生长和腐蚀行为。(c)2006爱思唯尔有限公司保留所有权利。
Semiconductor properties of passive films formed on the Fe-18Cr alloy in a borate buffer solution (pH = 8.4) and 0.1 M H2SO4 solution were examined using a photoelectrochemical spectroscopy and an electrochemical impedance spectroscopy. Photo current reveals two photo action spectra that derived from outer hydroxide and inner oxide layers. A typical n-type semiconductor behaviour is observed by both photo current and impedance for the passive films formed in the borate buffer solution. On the other hand, a negative photo current generated, the absolute value of which decreased as applied potential increased in the sulfuric acid solution. This indicates that the passive film behaves as a p-type semiconductor. However, Mott-Schottky plot revealed the typical n-type semiconductor property. It is concluded that the passive film on the Fe-18Cr alloy formed in the borate buffer solution is composed of both n-type outer hydroxide and inner oxide layers. On the other hand, the passive film of the Fe-18Cr alloy in the sulphuric acid consists of p-type oxide and n-type hydroxide layers. The behaviour of passive film growth and corrosion was discussed in terms of the electronic structure in the passive film. (c) 2006 Elsevier Ltd. All rights reserved.