B_4C/B_6O核-壳结构五次孪晶纳米线

B_4C/B_6O core-shell nanowire with a five-fold twinned structure

核壳结构纳米线是一类具有可调控物理特性的一维纳米材料。本文报道一种具有B4C核心,B6O壳层的五次孪晶纳米线。B4C和B6O同属于α菱方富硼化合物,二者的点阵参数相近。对单根纳米线的电子衍射、高分辨电子显微学分析,确定了纳米线的五次循环孪晶结构,纳米线芯部成分为B4C,表面具有B6O外延层。明场形貌像及能量过滤像分析表明该纳米线具有非对称截面形貌。通过系列温度合成实验可以预见,进一步调节原料配比、合成温度等因素,可大规模合成具有B4C/B6O核壳结构的五次循环孪晶纳米线,这将有助于进一步研究和应用α菱方硼化物纳米线的高温热电特性。

Core-shell nanowires are special one-dimensional nanomaterials with tunable physical properties. We report a B4C/B60 core-shell nanowire With five-fold cyclic twinned structure. Both B4C and B60 belong to α-rhombohcdral boron-rich materials and have similar lattice parameters. The combination of electron diffraction and high-resolution electron microscopy analysis for an individual nanowire not only reveals its five-fold cyclic twinned structure, but also the core-shell structure with a B4C core and an epitaxial B60 shell. Analysis of the bright field and energy-filtered images indicates that the nanowire has an asymmetric corss-sectional morphology. It is envisaged that large scale B4C/B60 core-shell nanowires with five-fold twinned structure can be synthesized through solid state reaction by tuning the ratio of the starting materials, synthesis atmosphere and temperature. It will be of a benefit to further investigation and application of high-temperature thermoelectric properties of ot-rbombohedral boron-rich nanowires.