AN IN-SITU STUDY OF THE SURFACE PHASE-TRANSITIONS OF ALPHA-FE2O3 BY X-RAY-ABSORPTION SPECTROSCOPY AT THE OXYGEN K-EDGE
AN IN-SITU STUDY OF THE SURFACE PHASE-TRANSITIONS OF ALPHA-FE2O3 BY X-RAY-ABSORPTION SPECTROSCOPY AT THE OXYGEN K-EDGE
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DOI：
10.1016/0168-583x(94)00408-0
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发表时间：
1995-05-01
影响因子：
1.3
通讯作者：
SAUNDERS, VR
中科院分区：
文献类型：
--
作者：
POLLAK, M;GAUTIER, M;SAUNDERS, VR
单晶α-Fe_2O_3的表面改性已被监测为离子蚀刻后，在超高真空和受控pO（2）下的不同原位热处理的函数。选择特定的（T，pO（2））条件以对应于本体Fe-O相图中Fe_3O_4和Fe_2O_3的稳定域。X射线吸收光谱进行，原位，在氧K边缘，使识别的相互转换，Fe 2 O3 Fe 3 O 4-x，在表面层。尽管在UHV下表面的再氧化是通过氧从本体的热扩散，但证据表明在10（-6）mbar氧下的再氧化涉及更复杂的机制。
Surface modifications of single crystal alpha-Fe2O3 have been monitored as a function of different in situ heat treatments after ion etching, in UHV and under controlled pO(2). The particular (T, pO(2)) conditions were chosen to correspond to the stability domain of Fe3O4 and Fe2O3 in the bulk Fe-O phase diagram. X-ray absorption spectroscopy was performed, in-situ, at the oxygen K edge, enabling the identification of the interconversion, Fe2O3 Fe3O4-x, in the surface layers. Whereas re-oxidation of the surface under UHV is by thermal diffusion of oxygen from the bulk, the evidence suggests that re-oxidation under 10(-6) mbar of oxygen involves a more complex mechanism.