In Situ TEM Observation of a Microcrucible Mechanism of Nanowire Growth
In Situ TEM Observation of a Microcrucible Mechanism of Nanowire Growth
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DOI：
10.1126/science.1251594
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发表时间：
2014-05-09
期刊：
影响因子：
56.9
通讯作者：
Hall, Simon R.
中科院分区：
文献类型：
--
作者：
Boston, Rebecca;Schnepp, Zoe;Hall, Simon R.
金属氧化物纳米线的生长可以通过多种机制进行，如螺位错、气-液-固过程或籽晶生长。透射电子显微镜可以分辨纳米线，但总是缺乏直接观察纳米线形成的设施。我们使用配备了原位加热阶段的透射电子显微镜来跟踪四元金属氧化物纳米线的生长。视频率成像显示，碳酸钡纳米颗粒通过含有铜和氧化钇的多孔基质扩散，随后充当Y2BaCuO5纳米线到达表面后生长的催化位置。结果表明，多孔基质粗糙表面上的位置起到了微熔炉的作用，从而为高温下驱动金属氧化物纳米线生长的机制提供了深入的了解。
The growth of metal oxide nanowires can proceed via a number of mechanisms such as screw dislocation, vapor-liquid-solid process, or seeded growth. Transmission electron microscopy (TEM) can resolve nanowires but invariably lacks the facility for direct observation of how nanowires form. We used a transmission electron microscope equipped with an in situ heating stage to follow the growth of quaternary metal oxide nanowires. Video-rate imaging revealed barium carbonate nanoparticles diffusing through a porous matrix containing copper and yttrium oxides to subsequently act as catalytic sites for the outgrowth of Y2BaCuO5 nanowires on reaching the surface. The results suggest that sites on the rough surface of the porous matrix act as microcrucibles and thus provide insights into the mechanisms that drive metal oxide nanowire growth at high temperatures.