A photoelectrochemical and ESCA study of passivity of amorphous nickel-valve metal alloys
A photoelectrochemical and ESCA study of passivity of amorphous nickel-valve metal alloys
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非晶镍阀金属合金钝化的光电化学和ESCA研究
DOI：
10.1016/0010-938x(90)90188-b
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发表时间：
1990
影响因子：
8.3
通讯作者：
K. Hashimoto
中科院分区：
文献类型：
--
作者：
K. Asami;S. Chen;H. Habazaki;A. Kawashima;K. Hashimoto
采用光电化学和ESCA 方法，在303 K 的脱气硫酸中，在各种阳极电位下极化，在各种非晶NiTi 合金和纯钛上形成钝化膜。测量光电流作为波长、电势和合金成分的函数。所有样品均表现出正光电流。根据光电流谱，确定纯钛和非晶镍钛合金上的钝化膜的带隙能为 3.2 eV。光电流随着合金中Ti含量的增加而线性增加。与合金成分相比，Ni40Ti 合金上的钝化膜在所有检测的电位区域中均富含 Ti。因此，钝化膜中的光活性Ti离子由于Ni离子的存在而被稀释，导致比钝化膜组合物所预期的负面影响更大的负面影响。
Photoelectrochemical and ESCA methods were applied to the passive films formed on a variety of amorphous NiTi alloys and pure titanium in a deaerated sulfuric acid at 303 K polarized at various anodic potentials. Photocurrents were measured as a function of wavelength, potential and alloy composition. All the specimens showed positive photocurrent. From the photocurrent spectra, a band-gap energy of 3.2 eV was determined for the passive films on pure titanium and amorphous NiTi alloys. The photocurrent increased linearly with the Ti content in the alloys. The passive films on Ni40Ti alloy were enriched with Ti in all the potential regions examined in comparison with bulk alloy composition. Dilution of photoactive Ti ions in the passive film by the presence of Ni ions, therefore, results in a negative effect more than that expected from the passive film composition.