Co淀积到γ-Fe2O3表面的光电发射谱研究

在γ-Fe₂O₃表面蒸镀不同厚度Co,观察到低Co覆盖度,Co具有很大活力与O₂结合,而使Fe还原.在θ=0.2—0.8时,表面上形成类CoFe₂O₄.Co覆盖度进一步增加,Fe在表面偏析,Co开始形成第二层,破坏了形成这种氧化物的条件.因此,这种铁钴氧化物与单层或亚单层包钴磁粉磁性的改善可能有密切关系.关键词：

A STUDY OF Co EVAPOURATING ON γ-Fe-2O3 SURFACE BY PHOTOEMISSION SPECTROSCOPY

The γ-Fe₂O₃ surface evapourated with Co has been studied by photoemission spectros-copy. The results show that at low coverage, Co is very active and combined with the oxygen in γ-Fe₂O₃, while Fe in γ-Fe₂O₃ was reduced; at the coverage of 0.2-0.8 monolayer, some kind of CoFe₂O₄-like oxide was formed on the surface; with further Co coverage increasing, the Fe in the bulk began to segregate to the surface and the second monolayer of Co began to form on the surface, which destroyed the condition favourable to the formation of the oxide. We can conclude from these results that the magnetism improvement of magnetic powder coated with one- or sub- monolayer Co may have strong relation to the presence of this CoFe₂O₄-like oxide.