Lehrstuhl für Physikalische Chemie II and Interdisciplinary Center for Molecular Materials, Universität Erlangen-Nürnberg, Egerlandstraße 3, D-91058 Erlangen, Germany.
Phys Chem Chem Phys. 2011 Oct 14;13(38):17333-8. doi: 10.1039/c1cp20865a. Epub 2011 Aug 31.
Upon exposure to Fe(CO)(5), the formation of pure cubic Fe nanocrystals with dimensions up to ~75 nm is reported on ultra-thin SiO(x) films (thickness ≈ 0.5 nm) on Si(001), which have been prepared in situ under UHV conditions. The active centers for initial decomposition of Fe(CO)(5) resulting in the growth of the Fe clusters are proposed to be SiO sites. After nucleation at these sites, further crystal growth is observed due to autocatalytic dissociation of Fe(CO)(5) at room temperature. The density of the Fe clusters can be increased by irradiating the surface with a focused electron beam (15 keV) prior to gas exposure. The formation of the active SiO sites upon electron irradiation is attributed to oxygen desorption via the Knotek-Feibelman mechanism.
在 Fe(CO)(5) 的作用下，我们在 Si(001)上的 ultra-thin SiO(x) 薄膜（厚度约为 0.5nm）上成功制备出了高达~75nm 的纯立方 Fe 纳米晶体。这些薄膜是在 UHV 条件下原位制备的。我们提出，SiO 位是初始分解 Fe(CO)(5) 并导致 Fe 团簇生长的活性中心。在这些位置成核后，由于 Fe(CO)(5) 在室温下的自动催化分解，进一步的晶体生长得以观察到。在气体暴露之前，用聚焦电子束（15keV）辐照表面可以增加 Fe 团簇的密度。电子辐照后形成活性 SiO 位归因于通过 Knotek-Feibelman 机制脱除氧。
