Observation of surface reactions by a highly sensitive Raman spectroscopy

我们已经开展了拉曼研究，以了解各种有趣的表面和界面现象的机制。首先，我们构建了一个高灵敏度的拉曼测量系统。接下来，我们进行了如下的拉曼测量：(1)我们发现，经2800ﾟC热处理的石墨化中间相球体在强激光照射下的拉曼光谱发生了有趣的变化。当它们被强激光照射时，158Ocm^-1&gt；处的E2g带宽度减小，而1350 cm^-1&gt；处的D带强度增加，即这些量之间是负相关的。我们还观察到了石墨化中间相球体在强激光照射下的发光。为了解释这些现象，我们提出了一个模型，在该模型中，石墨化中间相球体中的芳香族分子之间的桥键被强激光照射打破。(2)TiCl3是生产聚烯烃的Ziegler-Natta催化剂的重要组成部分。为了阐明催化反应的机理，我们首先测量了α-TiCl3晶体的拉曼光谱。观察到的光谱有五个明显的谱带。通过对晶格振动的简正模分析，可以将这五个拉曼谱带归属为三个A_g模、一个E_g模和一个组合模A_g+E_g。

We have carried out a Raman study to understand the mechanisms of various interesting phenomena concerning surfaces and interfaces. First we have constructed a highly sensitive Raman measurement system. Next we have carried out Raman measurements as follows.(1)We have found that the Raman spectra of graphitized mesophase spherules, heat treated at 2800ﾟC, show interesting change under intense laser irradiation. When they are irradiated with an intense laser beam, the width of the E2g band at 158Ocm^<-1> decreases while the intensity of the D band at 1350cm^<-1> increases, i.e. the correlation between these quantities is negative. We have also observed luminescence from graphitized mesophase spherules under intense laser irradiation. In order to interpret these phenomena, we suggest a model in which the bridge bounds between aromatic molecules in the graphitized mesophase spherules are broken by intense laser irradiation.(2)TiCI_3 is an important component of the Ziegler-Natta catalyst for the production of polyolefins. In order to clarify the mechanism of catalytic reactions, we have measured the Raman spectra of the alpha-TiCl_3 crystal as a first step. The observed spectra show five clear bands. By a normal mode analysis of the lattice vibrations, the five Raman bands can be assigned to three A_g modes, one E_g mode, and one combination mode A_g+E_g.