Room-temperature oxidation of Ni(110) at low and atmospheric oxygen pressures
Room-temperature oxidation of Ni(110) at low and atmospheric oxygen pressures
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DOI：
10.1007/bf01046987
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发表时间：
1996-04-01
影响因子：
2.2
通讯作者：
Holloway, PH
中科院分区：
文献类型：
--
作者：
Lambers, ES;Dykstal, CN;Holloway, PH
本文研究了原子级洁净的（110）镍单晶在室温和纯氧或空气中，在1 × 10（-9）Pa至大气压下的氧化。X射线光电子能谱（XPS）和俄歇电子能谱（AES）的数据表明，标准制度的解离化学吸附，氧化物成核，氧化物横向生长聚结观察在低压下。NiO层在低压下聚结后，将样品暴露于大气氧气或空气中不会导致氧化物厚度在室温下进一步生长。相反，在O 1 s XPS峰上的高能肩部的生长表明在表面上形成Ni（OH）（2）。氢氧化物的存在是一致的高分辨率，电子能量损失光谱（HREELS）数据和化学位移的Ni 2 p光谱。当氧化层厚度不变时，氢氧化层厚度随高压下暴露时间的延长而减小。表面分析和低压技术是适当的室温下，环境氧化物形成的研究，并允许确定的动力学和反应产物的钝化镍的关键。
Oxidation of atomically clean (110) nickel single crystals has been studied at room temperature and in pure oxygen or air at pressures from 1 x 10(-9) torr to atmospheric. X-ray photoelectron (XPS) and Auger electron spectroscopic (AES) data indicate that the standard regimes of dissociative chemisorption, oxide nucleation, and oxide lateral growth to coalescence were observed at low pressures. After the NiO layer coalesced at low pressures, exposure of the sample to atmospheric oxygen or air did not cause further growth of the oxide thickness at room temperature. Instead the growth of a high-energy shoulder on the O 1s XPS peak indicated the formation of Ni(OH)(2) on the surface. The presence of the hydroxide is consistent with high-resolution, electron-energy-loss spectroscopy (HREELS) data and chemical shifts in the Ni 2p spectra. While the oxide thickness is constant, the hydroxide thickness ina eased with exposure and time at high pressure. Surface analysis and low-pressure techniques are appropriate for the study of room-temperature, ambient-oxide formation and allow a determination of the kinetics and reaction products critical to the passivation of Ni.