Self-organization of nanoneedles in Fe/GaAs (001) epitaxial thin film
Self-organization of nanoneedles in Fe/GaAs (001) epitaxial thin film
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DOI：
10.1063/1.2182017
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发表时间：
2006-03
影响因子：
4
通讯作者：
Yizhong Huang;Shou-Guo Wang;C. Wang;Z. Xie;D. Cockayne;R. Ward
中科院分区：
文献类型：
--
作者：
Yizhong Huang;Shou-Guo Wang;C. Wang;Z. Xie;D. Cockayne;R. Ward
当用垂直于样品表面的Ga+离子束在聚焦离子束中以3× 1017scincm 2的离子剂量辐照时，发现在Fe scinGaAs（001）外延薄膜中形成了良好排列的纳米针。这些纳米针，其轴垂直于原始样品表面，由GaAs纳米棒与位于顶部的Fe纳米岛组成。由GaAs衬底形成的GaAs纳米棒是结晶的，并且与GaAs衬底处于相同的晶体取向。Fe薄膜的结晶性质被离子溅射破坏，成为纳米晶Fe岛。正是薄Fe层负责纳米针的形成。由于Fe层的溅射速率不均匀，Fe层的离子溅射使样品表面粗糙化。Fe层的去除将衬底暴露于入射离子，其然后溅射衬底，导致纳米针的形成。
Well-aligned nanoneedles are found to form in a Fe∕GaAs (001) epitaxial thin film when irradiated with a Ga+ ion beam normal to the sample surface at an ion dose of 3×1017∕cm2 in a focused ion beam. These nanoneedles, with their axes perpendicular to the original sample surface, are composed of GaAs nanorods with Fe nanoislands situated at the top. The GaAs nanorods, formed from the GaAs substrate, are crystalline and in the same crystal orientation as the GaAs substrate. The crystalline nature of the Fe thin film is disrupted by the ion sputtering, becoming nanocrystalline Fe islands. It is the thin Fe layer that is responsible for the formation of the nanoneedles. The ion sputtering of the Fe layer roughens the sample surface due to the uneven sputtering rate of the Fe layer. The removal of the Fe layer exposes the substrate to the incident ions, which then sputter the substrate leading to the formation of the nanoneedles.