Surface structure of ¦Ã-Fe₂O₃(111)

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• 作者：Michael Bowker ; Graham Hutchings ; Philip R. Davies ; Dyfan Edwards ; Robert Davies ; Shamil Shaikhutdinov ; Hans-Joachim Freund
• 关键词：Iron oxide surfaces ; Maghemite ; ¦Ã Fe2O3 ; STM ; ISS ; LEED
• 刊名：Surface Science
• 出版年：2012
• 出版时间：November, 2012
• 年：2012
• 卷：606
• 期：21-22
• 页码：1594-1599
• 全文大小：909 K

文摘

The surface structure of ¦Ã-Fe₂O₃(111) has been investigated with a range of surface techniques. Two different surface structures were discovered depending upon surface preparation techniques. Sputtering followed by annealing in vacuum produced a reduced surface characterised by a (2 ¡Á 2) LEED pattern, whereas sputtering followed by annealing in 1 ¡Á 10^? 6 mbar oxygen produced a surface characterised by a (¡Ì3 ¡Á ¡Ì3)-R30¡ã LEED pattern. The latter appears to be a very low conductivity surface, whereas the former has the band gap expected for maghemite (~ 2.0 eV). We propose that the reduced surface is a magnetite-like layer, whereas the oxidised surface is an Fe₂O₃-like layer.