Abstract Two modulated structures caused by long-range ordering of oxygen vacancies have been observed in α-Fe 2 O 3 nanowires (NWs) produced after oxidation of Fe, one being ten times ( 3 0 3 ¯ 0 ) interplanar spacing and the other being six times ( 1 1 2 ¯ 0 ) interplanar spacing. Both types of oxygen vacancy ordering structures have a similar modulation periodicity of 1.45 or 1.50 nm with corresponding atomic ratios of Fe and O (Fe/O) of 0.7407 and 0.7273, respectively. The Fe/O ratios in the NWs with oxygen-vacancy ordering are very close to that of Fe 3 O 4 (0.7500). The similar Fe/O ratio between NWs and Fe 3 O 4 may explain the similar modulation periodicity of different oxygen-vacancy orderings. Electron energy-loss spectroscopy studies show that the Fe/O ratio of NWs is close to that of Fe 3 O 4 when oxygen atoms are not sufficient, which makes the NWs energetically favorable. The elucidation of the mechanism governing the formation of the modulated structures in α-Fe 2 O 3 NWs is critical for controlling the microstructure and correspondingly physicochemical properties of NWs.

中文翻译：

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α-Fe 2 O 3 纳米线中氧空位诱导调制结构的形成

摘要 在 Fe 氧化后产生的 α-Fe 2 O 3 纳米线 (NWs) 中观察到两种由氧空位长程有序引起的调制结构，一种是 10 倍 ( 3 0 3 ¯ 0 ) 的晶面间距，另一种是六倍 ( 1 1 2¯ 0 ) 晶面间距。两种类型的氧空位有序结构都具有相似的调制周期，分别为 1.45 或 1.50 nm，相应的 Fe 和 O 原子比（Fe/O）分别为 0.7407 和 0.7273。具有氧空位排序的 NW 中的 Fe/O 比率非常接近 Fe 3 O 4 (0.7500)。NWs 和 Fe 3 O 4 之间相似的 Fe/O 比率可以解释不同氧空位排序的相似调制周期。电子能量损失谱研究表明，当氧原子不足时，NWs 的 Fe/O 比接近 Fe 3 O 4 ，这使得 NW 在能量上是有利的。阐明控制α-Fe 2 O 3 纳米线中调制结构形成的机制对于控制纳米线的微观结构和相应的物理化学性质至关重要。