论文部分内容阅读
用XPS研究了金属Ni在不同温度下在空气和水中的氧化行为及生成的表面氧化物的热稳定性。结果表明氧化物除NiO以外还存在Ni_2O_3。在室温下长期暴露空气后Ni表面生成Ni_2O_3更明显。金属Ni在纯水中氧化比空气中慢得多。研究结果还表明:Ni表面氧化物的热稳定性与其生成时的温度密切有关。金属Ni在室温暴露空气生成的NiO在10~(-6)Pa真空中在300℃加热10min即可使其还原成金属Ni。该还原作用是NiO与表面碳氢化合物污染物之间的反应。然而,在200℃以上在空气中加热生成的NiO在相同条件下作真空热处理时不能使其还原成金属。最后本文对不同温度下生成的NiO有不同的热稳定性的原因进行了讨论。
The oxidation behavior of metal Ni in air and water at different temperatures and the thermal stability of the formed surface oxides were studied by XPS. The results show that there is Ni_2O_3 in addition to NiO. After long-term exposure to air at room temperature Ni Ni 2 O 3 surface is more obvious. Metallic Ni oxidizes in pure water much more slowly than in the air. The results also show that: the thermal stability of Ni surface oxide is closely related to the temperature at the time of its formation. Metal Ni NiO exposed to air at room temperature can be reduced to metal Ni by heating in vacuum at 10 ~ (-6) Pa for 10min at 300 ℃. This reduction is a reaction between NiO and surface hydrocarbon contaminants. However, NiO generated by heating in air above 200 ° C can not be reduced to metal under vacuum heat treatment under the same conditions. Finally, the reasons for the different thermal stability of NiO formed at different temperatures are discussed in this paper.