Higgins Jeremy M, Schmitt Andrew L, Guzei Ilia A, Jin Song
Department of Chemistry, University of Wisconsin-Madison,1101 University Avenue, Madison, Wisconsin 53706, USA.
J Am Chem Soc. 2008 Nov 26;130(47):16086-94. doi: 10.1021/ja8065122.
We report the synthesis, structural identification, and electrical properties of the first one-dimensional (1-D) nanomaterials of a semiconducting higher manganese silicide (MnSi(2-x)) with widths down to 10 nm via chemical vapor deposition of the single-source precursor Mn(CO)(5)SiCl(3). The complex Nowotny chimney ladder structure of these homologous higher manganese silicides, also referred to as Mn(n)Si(2n-m), MnSi(1.75), or MnSi(1.8), contributes to the excellent thermoelectric performance of the bulk materials, which would be enhanced by phonon scattering due to 1-D nanoscale geometry. The morphology, structure, and composition of MnSi(2-x) nanowires and nanoribbons are examined using electron microscopy and X-ray spectroscopy. Elaborate select area electron diffraction analysis on single-crystal nanowires reveals the phase to be Mn(19)Si(33), one of a series of crystallographically distinct higher manganese silicides that have a Nowotny chimney ladder structure. Electrical transport study of single nanowires shows that they are degenerately doped with a low resistivity (17 mohms x cm) similar to the bulk.
我们报道了通过单源前驱体Mn(CO)₅SiCl₃的化学气相沉积法合成的宽度低至10 nm的首个一维（1-D）半导体高锰硅化物（MnSi(2-x)）纳米材料、其结构鉴定及电学性质。这些同系高锰硅化物具有复杂的诺沃托尼烟囱梯结构，也被称为Mn(n)Si(2n-m)、MnSi(1.75)或MnSi(1.8)，这种结构有助于块状材料具有优异的热电性能，而一维纳米尺度的几何结构所导致的声子散射会增强这种性能。使用电子显微镜和X射线光谱对MnSi(2-x)纳米线和纳米带的形貌、结构及成分进行了研究。对单晶纳米线进行的精细选区电子衍射分析表明该相为Mn(19)Si(33)，它是一系列具有诺沃托尼烟囱梯结构的晶体学上不同的高锰硅化物之一。对单根纳米线的电输运研究表明，它们为简并掺杂，具有与块状材料相似的低电阻率（17毫欧厘米）。
