Varadwaj Kumar S K, Seo Kwanyong, In Juneho, Mohanty Paritosh, Park Jeunghee, Kim Bongsoo
Department of Chemistry, KAIST, Daejeon 305-701, Korea.
J Am Chem Soc. 2007 Jul 11;129(27):8594-9. doi: 10.1021/ja071439v. Epub 2007 Jun 14.
We report the synthesis of single-crystalline nanowires (NWs) of metastable Fe5Si3 phase via an iodide vapor transport method. Free-standing Fe5Si3 NWs are grown on a sapphire substrate placed on a Si wafer without the use of any catalyst. The typical size of the Fe5Si3 nanowires is 5-15 microm in length and 100-300 nm in diameter. Synthesis of the metastable phase is induced by composition-dependent nucleation from the gas-phase reaction. Depending on the concentration ratio of FeI2(g) to SiI4(g), different phases of iron silicides are formed. The growth of nanowires is facilitated by the initial nucleation of silicide particles on the substrate and further self-seeded growth of the NWs. The present work not only provides a method for the synthesis of metastable Fe5Si3 nanowires but also suggests that the phase controlled synthesis can be further optimized to produce other metal-rich silicide nanostructures for future spintronic devices.
我们报道了通过碘化物气相传输法合成亚稳相Fe5Si3的单晶纳米线（NWs）。在不使用任何催化剂的情况下，在放置于硅片上的蓝宝石衬底上生长出了独立的Fe5Si3纳米线。Fe5Si3纳米线的典型尺寸为长度5 - 15微米，直径100 - 300纳米。亚稳相的合成是由气相反应中成分依赖的成核作用诱导的。根据FeI2(g)与SiI4(g)的浓度比，会形成不同相的硅化铁。纳米线的生长通过衬底上硅化物颗粒的初始成核以及纳米线进一步的自种子生长得以促进。目前的工作不仅提供了一种合成亚稳Fe5Si3纳米线的方法，还表明相控合成可以进一步优化，以生产用于未来自旋电子器件的其他富金属硅化物纳米结构。
