Department of Chemistry, KAIST, Daejeon 305-701, Korea.
ACS Nano. 2012 Oct 23;6(10):8652-7. doi: 10.1021/nn302141w. Epub 2012 Sep 17.
We have synthesized epitaxially grown freestanding FeSi nanowires (NWs) on an m-Al(2)O(3) substrate by using a catalyst-free chemical vapor transport method. FeSi NW growth is initiated from FeSi nanocrystals, formed on a substrate in a characteristic shape with a specific orientation. Cross-section TEM analysis of seed crystals reveals the crystallographic structure and hidden geometry of the seeds. Close correlation of geometrical shapes and orientations of the observed nanocrystals with those of as-grown NWs indicates that directional growth of NWs is initiated from the epitaxially formed seed crystals. The diameter of NWs can be controlled by adjusting the composition of Si in a Si/C mixture. The epitaxial growth method for FeSi NWs via seed crystals could be employed to heteroepitaxial growth of other compound NWs.
我们使用无催化剂的化学气相传输法，在 m-Al(2)O(3) 衬底上外延生长了独立的 FeSi 纳米线 (NWs)。FeSi NW 的生长是从 FeSi 纳米晶开始的，这些纳米晶以特定的形状和特定的取向在衬底上形成。种子晶体的横截面 TEM 分析揭示了种子的晶体结构和隐藏的几何形状。观察到的纳米晶的几何形状和取向与所生长 NW 的取向密切相关，这表明 NW 的定向生长是从外延形成的种子晶体开始的。通过调整 Si/C 混合物中 Si 的成分，可以控制 NW 的直径。通过种子晶体的外延生长方法可以用于其他化合物 NW 的异质外延生长。
