Development of Method to Separation and Punfication 0f Novel-Fullerene Corn-pound Materials Using Plasma Chromatography

在富勒烯(K^+-C)等离子体成膜实验中，通过控制K~+和C~(-60)离子流入衬底的能量和流量，成功地形成了面内金属富勒烯K@C&t；60。由于K@C&lt；60&gt；与C&lt；60&gt；的产率最高为30%，通常为5~10%或更少，但很难阐明等离子体效应与包埋机理之间的关系。从上述观点出发，实验是在钠富勒烯(Na^+-C^-&lt；60)等离子体上进行的，其中Na+的直径比K+的直径小。根据在衬底上形成的薄膜的质量分析，观察到与NaEndohedral Fullereoe相对应的大的质谱峰(Na(@)C&lt；60&gt；)。结果表明，Na(@)C_(60)与C_(60)的平均强度比为30~50%。此外，在较窄的衬底区域内，Na(@)C&lt；60&gt；的产额比达到200%或更高。改变衬底偏压时，Na(@)C&lt；60&gt；的平均谱峰强度在特定的电压下出现最大值。在衬底的狭窄区域，在薄膜的图像上观察到了许多中心周围有暗阴影的C&lt；60&gt；分子。高分辨电子显微镜成像的圆形材料被认为是笼子内包裹着Na的C；lt；60&gt；，因为Na+的直径几乎与暗影直径相对应。可以说，含有Na@C；60&gt；的Na-C；60&gt；复合材料的大量生产为成分分析和结构观察提供了便利，以期澄清其物理化学性质。这项工作对于建立具有新功能的富勒基薄膜的形成方法也具有重要意义。

The endohedral metallofullerene K@C_<60> was successfully formed by the energy and flux control of K^+ and C^-_<60> ions flowing into substrates in experiments of the thin-film formation with a potassiumfullerene (K^+_-C^-_<60>) plasma. Since the K@C_<60> production ratio to C_<60> was at most 30% and usually 5〜10% or less, however, it was difficult to clarify the relation between the plasma effect and encapsulation mecharuism. From the abovementioned viewpoint, the experiments were carried out by a sodiumfullerene (Na^+_-C^-_<60>) plasma, where the diameter of Na^+ is srmaller than that of K^+. The following results were obtained.According to the mass analysis of thin films formed on the substrates, the large massspectrum peak (Na(@)C_<60>) corresponding to the Naendohedral fullereoe is observed. The average intensity ratio of Na(@)C_<60> to C_<60> is turned out to be 30〜50%. Moreover, the Na(@)C_<60> production ratio to C_<60> in a narrow region of the substrate attains to 200% or more.When the substrate bias is chansed, the average spectrumpeak intensity of Na(@)C_<60> is found to give the maximum value at a specific voltage.The composition and structure of the thin film are directly investigated by the highresolution electron microscope (HREM) observation. A lot of C_<60> molecules with dark shadows around the centers are observed over the image of the thin film in the narrow region of the substrate. The round material imaged by the HREM is considered to be C_<60> encapsulating Na inside the cage, because the Na^+ diameter almost corresponds to the dark shadow diameter.It can be said that a large amount of production of the Na-C_<60> compound materials containing Na@C_<60> facilitates the constituent analysis and structure observation for the purpose of clarifying their physical and chemical properties. This work is also important in the sence of establishing the method of forming fullerenebased thin films with new functions.