SURFACE PLASMON POLARITON-AIDED RAMAN SPECTROSCOPIC STUDY ON FILM GROWTH MECHANISMS

表面等离子体偏振辅助拉曼光谱研究薄膜生长机制

基本信息

批准号：
05453083
负责人：
HATTA Aritada
金额：
$ 3.97万
依托单位：
TOHOKU UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (B)
财政年份：
1993
资助国家：
日本
起止时间：
1993 至 1995
项目状态：
已结题

项目摘要

1) In order to investigate the adsorption of p-aminothiophenol (PATP) on silver, Raman scattering experiments were performed by exciting surface plasmon polaritons on Ag island films. The silver films were prepared by vacuum evaporation as a mass thickness of 5nm on BaF_2 plates. The plates were dipped into ethanol solutions containing 1 mM PATP.The Raman spectra were measured as a function of dipping time. At the initial stages of the adsorption of PATP on Ag, the Raman signals from PATP increased in proprtion to the square root of dipping time, suggesting that the adsorption rate was conditioned by the diffusion of PATP in the solution. The Raman band due to the Ag-S stretching vibration was also detected at near 220cm^<-1>, which demonstrates a direct contact of the S atom with Ag. These results were supported by our FT-IR experiments.2) Raman scattering was measured for iron pentacarbonyl (IPC) deposited in vacuum at 120K on flat and rough Ag film surfaces. At elevated temperatures IPC was molecularly desorbed from the surface. Illumination of IPC with UV light from a low pressure Hg lamp decreased the Raman signals, but no significant changes were observed in the spectra. Upon heating the substrate up to 200K under UV irradiation, the two C-O stretch bands in the 2000 cm^<-1> region disappeared and, instead, two novel bands appeared. These spectral changes are thought to arise from a structural change of IPC or its conversion into other Fe-carbonyl species. Another spectral change was found near 260K under UV illumination. It should be noted that the Raman signals were more intense on rough silver surfaces than on flat ones. This enhancement of Raman signals from the rough surfaces are explained by the SPP excitations of Ag. Thus, through these investigations, we could demonstrate the usefulness of the SPP-aided Raman spectroscopy in getting information on surface reactions and deposition processes, most of which had been ambiguous.

1）为了研究p-氨基硫醇（PATP）在银色的吸附，拉曼散射实验是通过AG Island膜上令人兴奋的表面等离子体极化剂进行的。银膜是通过真空蒸发作为BAF_2板上5nm的质量厚度制备的。将板浸入含有1 mM PATP的乙醇溶液中。拉曼光谱的测量是浸入时间的函数。在PATP对Ag的吸附的初始阶段，PATP的拉曼信号在浸入时间的平方根上增加到了平方根，这表明吸附速率是由PATP在溶液中扩散的条件。在接近220厘米^<-1>的接近时，还检测到由于Ag-S拉伸振动引起的拉曼带，这表明S原子与Ag的直接接触。我们的FT-IR实验支持了这些结果。2）2）拉曼散射测量了在平面和粗糙的Ag膜表面上，在120K的真空中沉积在真空中的铁五经（IPC）。在升高的温度下，IPC从表面分子分子分子。用低压HG灯照亮IPC的IPC降低了拉曼信号，但在光谱中未观察到显着变化。在将基材加热到紫外线照射下最高为200K时，在2000 cm^<-1>区域中的两个C-O弹力带消失了，相反，出现了两个新型带。这些频谱变化被认为是由IPC的结构变化或其转化为其他Fe键盘物种引起的。在紫外线照明下260k附近发现了另一种光谱变化。应当指出的是，拉曼信号在粗糙的银色表面上比在扁平表面上更强烈。 AG的SPP激发解释了来自粗糙表面的拉曼信号的这种增强。因此，通过这些研究，我们可以证明SPP辅助的拉曼光谱法在获取有关表面反应和沉积过程的信息中的有用性，其中大多数是模棱两可的。