Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, Wisconsin 53706, USA.
ACS Nano. 2011 Apr 26;5(4):3268-77. doi: 10.1021/nn200387y. Epub 2011 Mar 11.
We present the chemical vapor deposition (CVD) reactions of the single source precursor Fe(SiCl(3))(2)(CO)(4) over Si, Ge, CoSi(2)/Si, and CoSi/Si substrates to explore the growth and doping processes of silicide nanowires (NWs). Careful investigation of the composition and morphology of the NW products and the intruded silicide films from which they nucleate revealed that the group IV elements (Si, Ge) in the NW products originate from both the precursor and the substrate, while the metal elements incorporated into the NWs (Fe, Co) originate from vapor phase precursor delivery. The use of a Ge growth substrate enabled the successful synthesis of Fe(5)Si(2)Ge NWs, the first report of a metal silicide-germanide alloy NW. Further, investigation of the pyrolysis of the CoSiCl(3)(CO)(4) precursor revealed independent delivery of Co and Si species during CVD reactions. This understanding enabled a new, more robust two-precursor synthetic route to Fe(1-x)Co(x)Si alloy NWs using Fe(SiCl(3))(2)(CO)(4) and CoCl(2).
我们展示了单源前驱物 Fe(SiCl(3))(2)(CO)(4) 在 Si、Ge、CoSi(2)/Si 和 CoSi/Si 衬底上的化学气相沉积 (CVD) 反应，以探索硅化物纳米线 (NW) 的生长和掺杂过程。对 NW 产物的组成和形貌以及它们成核的侵入硅化物薄膜的仔细研究表明，NW 产物中的 IV 族元素 (Si、Ge) 既来自于前驱物也来自于衬底，而掺入 NWs 中的金属元素 (Fe、Co) 则来自气相前驱物的输送。使用 Ge 生长衬底成功合成了 Fe(5)Si(2)Ge NWs，这是首例金属硅化物-锗化物合金 NW 的报道。此外，对 CoSiCl(3)(CO)(4) 前驱物的热解研究表明，在 CVD 反应中 Co 和 Si 物种的输送是独立的。这种理解为使用 Fe(SiCl(3))(2)(CO)(4) 和 CoCl(2) 合成 Fe(1-x)Co(x)Si 合金 NWs 提供了一种新的、更稳健的双前驱物合成途径。
