School of Chemistry and Bio21 Institute, University of Melbourne , Parkville, Victoria 3010, Australia.
Nano Lett. 2014 Jul 9;14(7):3799-808. doi: 10.1021/nl5009053. Epub 2014 Jun 26.
We present a scanning transmission electron microscopy-electron energy loss spectroscopy (STEM-EELS) investigation of gold nanosphere chains with lengths varying from 1 to 5 particles. We show localized EELS signals from the chains and identify energy-loss peaks arising due to l = 1, 2, 3, 4, and 5 plasmon modes through the use of EELS mapping. We also show the evolution of the energy of these modes as the length of a given chain increases, and we find that a chain containing N particles can accommodate at least N experimentally observable modes, in addition to the transverse mode. As the chain length is increased by the addition of one more gold particle to the chain, the new N + 1 mode becomes the highest energy mode, while the existing modes lower their energy and eventually asymptote as they delocalize along the chain. We also show that modes become increasingly difficult to detect with the EELS technique as l approaches N. The data are compared to numerical simulations.
我们通过扫描透射电子显微镜-电子能量损失谱（STEM-EELS）研究了长度从 1 到 5 个粒子的金纳米球链。我们展示了来自链的局域 EELS 信号，并通过 EELS 映射识别了由于 l = 1、2、3、4 和 5 等离子体模式而产生的能量损失峰。我们还展示了随着给定链长度的增加，这些模式的能量的演化，并且我们发现包含 N 个粒子的链除了横向模式之外还可以容纳至少 N 个实验可观察到的模式。随着通过向链中添加一个金粒子来增加链的长度，新的 N + 1 模式成为最高能量模式，而现有模式降低其能量并最终随着它们沿链去局域化而渐近。我们还表明，随着 l 接近 N，EELS 技术检测到的模式变得越来越困难。将数据与数值模拟进行了比较。
