Structural determination of metal nanoparticles from their vibrational (phonon) density of states
Structural determination of metal nanoparticles from their vibrational (phonon) density of states
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DOI：
10.1021/jp510666v
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发表时间：
2015-03
期刊：
影响因子：
--
通讯作者：
I. Garzón;H. E. Sauceda
中科院分区：
文献类型：
--
作者：
I. Garzón;H. E. Sauceda
可以使用核共振非弹性X射线或等离子体共振拉曼散射来测量尺寸在2和6 nm之间的金属纳米颗粒的振动（声子）态密度。在这项工作中，我们提出了原子的计算，基于半经验紧束缚多体古普塔势，振动态密度（VDOS）的面心立方（FCC），十面体，和二十面体（ICO）的金和银纳米粒子的尺寸为1.4 nm（约2000个原子）。计算的VDOS与实验数据进行比较，最近发表的金和银纳米粒子的大小相似，通过等离子体共振拉曼散射。计算和测量的VDOS之间的最佳协议是获得两种金属纳米粒子的ICO形态。这些结果表明，实验样品中的大多数纳米颗粒应该具有二十面体结构。本研究还表明，在分子系统和小团簇的情况下，振动光谱的分子。
The vibrational (phonon) density of states of metal nanoparticles with size between 2 and 6 nm can be measured using nuclear resonant inelastic X-ray or plasmon resonance Raman scattering. In this work, we present atomistic calculations, based on a semiempirical tight-binding many-body Gupta potential, of the vibrational density of states (VDOS) for face-centered cubic (FCC), decahedral, and icosahedral (ICO) gold and silver nanoparticles with sizes ∼4 nm (∼2000 atoms). The calculated VDOS are compared with experimental data, recently published for gold and silver nanoparticles of similar size, obtained through plasmon resonance Raman scattering. The best agreement between the calculated and measured VDOS’s is obtained for the ICO morphology for both metal nanoparticles. These results indicate that most of the nanoparticles in the experimental samples should have icosahedral structures. The present study also shows that, as in the case of molecular systems and small clusters, vibrational spectroscopy of m...