Houplin J, Amiaud L, Dablemont C, Lafosse A
Univ Paris-Sud, Institut des Sciences Moléculaires d'Orsay (ISMO), UMR 8214, Orsay, F-91405, France.
Phys Chem Chem Phys. 2015 Nov 11;17(45):30721-8. doi: 10.1039/c5cp04067a.
Low energy electron scattering on terphenylthiol (TPT, HS-(C6H4)2-C6H5) self-assembled monolayers (SAMs) deposited onto gold was investigated using high resolution electron energy loss spectroscopy (HREELS) by recording specular elastic and inelastic excitation functions. The electron elastic reflectivity could be directly compared to the sample density-of-states (DOS) above vacuum level. A high reflectivity region was observed in the range 7.2-8.6 eV. Inelastic excitation functions were studied to get insights into the mechanisms involved in the excitation of a selection of vibrational modes (dipolar and impact scattering). In particular, a resonant mechanism was observed in the excitation of the stretching mode ν(CC) at 196 meV. The purely resonant contribution to the electron-induced excitation of the stretching modes ν(CH) (379 meV) could be extracted from the overtone excitation. It is located at 7.2 eV above the vacuum level and is characterized by a width of 3.4 eV.
通过记录镜面弹性和非弹性激发函数，利用高分辨率电子能量损失谱（HREELS）研究了沉积在金上的三联苯硫醇（TPT，HS-(C6H4)2-C6H5）自组装单分子层（SAMs）上的低能电子散射。电子弹性反射率可直接与高于真空能级的样品态密度（DOS）进行比较。在7.2 - 8.6 eV范围内观察到一个高反射率区域。研究了非弹性激发函数，以深入了解一系列振动模式（偶极散射和碰撞散射）激发所涉及的机制。特别是，在196 meV处的拉伸模式ν(CC)激发中观察到了共振机制。拉伸模式ν(CH)（379 meV）的电子诱导激发的纯共振贡献可从泛音激发中提取。它位于高于真空能级7.2 eV处，特征宽度为3.4 eV。
