钝化时间对Fe30Mn9Al合金钝化膜半导体特性影响

Effects of passivating time on the semiconductor properties of passive film formed on an Fe30Mn9Al alloy

摘要:

运用电化学阳极钝化技术对Fe30Mn9Al合金在1mol/L Na₂SO₄溶液中进行不同时间的表面钝化处理；利用俄歇电子能谱(AES)、X射线光电子能谱(XPS)表面分析技术及Mott-Schottky曲线测试技术研究钝化时间对Fe30Mn9Al合金钝化膜的组成结构与半导体特性的影响。研究结果表明：Fe30Mn9Al合金在1 mol/L Na₂SO₄溶液中钝化15 min所得钝化膜分为内外两层,外层具有n型半导体特征,由Fe₂O₃、Al₂O₃、Mn₂O₃、FeOOH和AlOOH组成,内层具有p型半导体特征,由MnO组成。随着钝化时间由15 min增至5 h,钝化膜中的MnO溶解,Mn含量降低,Fe、Al填充Mn留下的空位在膜内富集,Fe、Al氧化物转变为Fe、Al氢氧化物,钝化膜由FeOOH、AlOOH和Mn₂O₃组成,具有n型半导体特征。与钝化15 min所得钝化膜相比,钝化5 h所得钝化膜的施主浓度N_D由2.58′10₂₁ cm_-3降至1.96′10₂₁ cm_-3,平带电位E_fb由-283 mV降至-366 mV,钝化膜的保护性能提高。

Abstract:

The effect of anodic aging time on the constitution, structure and semiconductor properties of passive film formed on an Fe30Mn9Al alloy in 1mol/L Na₂SO₄solution were studied by using combined Auger electron spectroscopy (AES) / X-ray photoelectron spectroscopy (XPS) analysis and the measurement of Mott-Schottky curves. The passive film formed on Fe30Mn9Al alloy in 1mol/L Na₂SO₄solution for 15 min has two layers of inside and outside, and the outside layer has the characteristics of n-type semiconductor, composed of Fe₂O₃, Al₂O₃, Mn₂O₃, FeOOH and AlOOH, the inside layer has the characteristics of p-type semiconductor, composed of MnO. The passive film formed on Fe30Mn9Al alloy in 1mol/L Na₂SO₄solution for 5 h has the characteristics of n-type semiconductor, composed of FeOOH , AlOOH and Mn₂O₃. As the anodic aging time increases from 15 min to 5 h, the Al and Fe contents are enriched and the Mn is depleted, MnO dissolved, the Al and Fe oxides are changed to the Al and Fe hydroxides; The donor densities N_D of the passive film decreased from 2.58′10₂₁ cm_-3 to 1.96′10₂₁ cm_-3, the flat band potential E_fb decreased from -283 mV to -366 mV, respectively.