The Interaction of N2 with Iron on W(110), Pd(111) and Rh(111)
The Interaction of N2 with Iron on W(110), Pd(111) and Rh(111)
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N2 与铁在 W(110)、Pd(111) 和 Rh(111) 上的相互作用
DOI：
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发表时间：
1997
期刊：
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通讯作者：
H. Freund
中科院分区：
文献类型：
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作者：
K. Homann;H. Kuhlenbeck;H. Freund
用角分辨光谱(ARUPS)研究了分子氮与W(110)、Pd(111)和Rh(111)上的铁薄膜的相互作用。W(110)上厚度达2层的铁层被应变，从而获得衬底的晶格常数。此外，还研究了一种云纹状超结构。与Fe(110)的结果相反，我们发现在应变的Fe/W(110)上存在低温下的分子吸附以及氮分子的解离。与计算结果一致，我们发现Fe/W(110)的3d能带密度上移，这可能是Fe/W(110)的反应性比Fe(110)更强的原因。为了研究衬底对氮气相互作用的影响，我们研究了不同厚度的薄膜。由于在Pd(111)和Rh(111)衬底上形成的假晶态铁膜的应变介于Fe/W(110)和非应变Fe(110)之间，因此研究了这两种衬底上的铁层。我们FMD表面化合物的形成和铁在高温下扩散到衬底。化合物膜的化学活性介于W(110)面上的假象Fe和Fe(110)面上的假象Fe之间。
We have studied the interaction of molecular nitrogen with thin iron films on W(110), Pd(111) and Rh(111) using angular resolved spectroscopy (ARUPS). Iron layers on W(110) with thicknesses of up to 2 layers are strained thereby acquiring the lattice constant of the substrate. Also a moire like superstructure has been studied. In contrast to results obtained for Fe(110) we find molecular adsorption at low temperatures as well as dissociation of nitrogen molecules on strained Fe/W(110). In agreement with calculations we find an upward shift of the iron 3d band density which might be the reason for the enhanced reactivity of Fe/W(110) as compared to Fe(110). In order to study the influence of the substrate on the interaction with nitrogen we have investigated films with different thickness. Iron layers on Pd(lll) and Rh(lll) have been studied since the strain of pseudomorphic iron films on these substrates is intermediate between that of Fe/W(110) and unstrained Fe(110). We fmd the formation of surface compounds and iron diffusion into the substrate at elevated temperatures. The chemical activity of the compound films is intermediate between those of pseudomorphic Fe on W(110) and Fe(110).