Composition-Tuned ConSi Nanowires: Location-Selective Simultaneous Growth along Temperature Gradient

Department of Chemistry, KAIST, Daejeon 305-701, Korea.
ACS Nano (Impact Factor: 12.03). 05/2009; 3(5):1145-50. DOI: 10.1021/nn900191g
Source: PubMed

ABSTRACT We report the simultaneous and selective synthesis of single-crystalline Co(n)Si NWs (n = 1-3) and their corresponding crystal structures--simple cubic (CoSi), orthorhombic (Co(2)Si), and face-centered cubic (Co(3)Si)--following a composition change. Co(n)Si NWs were synthesized by placing the sapphire substrates along a temperature gradient. The synthetic process is a successful demonstration of tuning the chemical composition in Co(n)Si NWs. The synthesis and detailed crystal structure of single-crystalline Co(2)Si and Co(3)Si are reported for the first time including the bulk and the nanostructure phases. The electrical and magnetic properties of Co(2)Si NWs are investigated and compared with those of CoSi NWs.

  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: an optional and free service which allows authors to make their results available to the research community as soon as possible after acceptance. After a manuscript has been technically edited and formatted, it will be removed from the "Just Accepted" Web site and published as an ASAP article. Please note that technical editing may introduce minor changes to the manuscript text and/or graphics which may affect the content, and all legal disclaimers that apply to the journal pertain. In no event shall TUP be held responsible for errors or consequences arising from the use of any information contained in these "Just Accepted" manuscripts. To cite this manuscript please use its Digital Object Identifier (DOI®), which is identical for all formats of publication.
    Nano Research 07/2014; 10.1007/s12274-014-0538-4(12). DOI:10.1007/s12274-014-0538-4 · 6.96 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: This review covers recent developments in our group regarding the synthesis, characterization and applications of single-crystalline one-dimensional nanostructures based on a wide range of material systems including noble metals, metal silicides and metal germanides. For the single-crystalline one-dimensional nanostructures growth, we have employed chemical vapor transport approach without using any catalysts, capping reagents, and templates because of its simplicity and wide applicability. Au, Pd, and Pt nanowires are epitaxially grown on various substrates, in which the nanowires grow from seed crystals by the correlations of the geometry and orientation of seed crystals with those of as-grown nanowires. We also present the synthesis of numerous metal silicide and germanide 1D nanostructures. By simply varying reaction conditions, furthermore, nanowires of metastable phase, such as and , and composition tuned cobalt silicides (CoSi, , ) and iron germanides ( and ) nanowires are synthesized. Such developments can be utilized as advanced platforms or building blocks for a wide range of applications such as plasmonics, sensings, nanoelectronics, and spintronics.
    Bulletin- Korean Chemical Society 09/2012; 33(9). DOI:10.5012/bkcs.2012.33.9.2830 · 0.84 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Manganese silicides nanostructures showed great potential applications in microelectronic and optoelectronic devices. In this study, Mn4Si7 and Si–Mn4Si7 axial heterostructure nanowire arrays were synthesized by the in-situ reaction between Si nanowire arrays and MnCl2. Depending on the reaction durations and processes, structures (Mn4Si7 nanowires or Si–Mn4Si7 axial heterostructure nanowires) and lengths of the Mn4Si7 nanowires could be readily tuned. Phase identification were performed by the XRD, TEM, HRTEM, and SAED means, which results indicated that the as-synthesized nanowire is Nowotny chimney ladder (NCL) structure Mn4Si7 with a tetragonal structure. The Mn4Si7 nanowire arrays exhibited enhanced ferromagnetism comparing with other bulk higher manganese silicides. The Curie temperature of the Mn4Si7 nanowire arrays is over 300 K, which is much higher than that of the previous reports. Because of the good compatibility with Si-based nanowire devices and many favorable properties, these Mn4Si7 nanowire arrays have wide potential applications in the Si-based self-assembly nanowire devices.
    The Journal of Physical Chemistry C 01/2013; 117(5):2377–2381. DOI:10.1021/jp310700r · 4.84 Impact Factor