Morphological evolution of neodymium boride nanostructure growth by chemical vapor deposition
Morphological evolution of neodymium boride nanostructure growth by chemical vapor deposition
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DOI：
10.1021/jp901717h
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发表时间：
2009-05
影响因子：
3.7
通讯作者：
Gonghua Wang;J. Brewer;J. Y. Chan;D. Diercks;C. L. Cheung
中科院分区：
文献类型：
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作者：
Gonghua Wang;J. Brewer;J. Y. Chan;D. Diercks;C. L. Cheung
电子发射材料的纳米尺度驱动设计可以通过利用场增强效应来显著提高其作为场致电子发射阴极的总体效率。六硼化钕（NdB 6）的难熔性质和低功函数（1.6eV）表明，高纵横比的NdB 6纳米结构是作为高效场发射阴极的潜在候选者。在这里，我们报告的形态演变的一维硼化钕纳米结构合成使用钯纳米粒子催化化学气相沉积作为反应温度的函数。扫描电子显微镜数据显示，明智地选择反应温度（795 - 940 °C）可以导致卷曲纳米线或高纵横比纳米线的优先生长。透射电子显微镜和选区电子衍射表明，这些纳米结构的结晶度的变化从无定形，多晶，单晶的反应温度。
Nanoscale-driven design of electron emission materials can significantly increase their overall efficiency as cathodes for field-induced electron emission by taking advantage of the field enhancement effect. The refractory nature and low work function (1.6 eV) of neodymium hexaboride (NdB6) suggest that high aspect ratio NdB6 nanostructures are potential candidates as efficient field emission cathodes. Here we report the morphological evolution of one-dimensional neodymium boride nanostructures synthesized using palladium-nanoparticle-catalyzed chemical vapor deposition as a function of reaction temperature. Scanning electron microscopy data show that judicious choices of reaction temperatures (795−940 °C) can lead to the preferential growth of curly nanowires or high aspect ratio nanowires. Transmission electron microscopy and selected area electron diffraction reveal that the crystallinity of these nanostructures changes from amorphous, to polycrystalline, to single crystalline as the reaction temperatu...