| Research Abstract |
In the C_<60> and carbon nanotube systems, characteristic interactions with rare gases are found in addition to the interaction with nitrogen, hydrogen and so on.
Na-C_<60> system does not show the superconductivity, while ternary system with nitrogen or hydrogen becomes to have a superconductive phase. For Na-H-C_<60>, C_<60> and carbon nanotube systems, the interactions with rare gases such as He, Ne, Ar, Kr and Xe are investigated by means of mass-analyzed thermal desorption, X-ray photoelectron spectroscopy, ESR and calculations of electronic states. The samples of Na-H-C_<60>, C_<60> and carbon nanotubes are transferred in-situ to the tube equipped with the ultra-high vacuum system, and heated at 653K or 1073K.Then the samples are exposed to gases under the conditions of 273-473K and around 1 atm. When the sample is heated, the desorbed gases are analyzed by use of mass analyzers. By using the glove bag, the sample is transferred in-situ to the X-ray photoelectron spectrometer (VG ESCA LAB MkII), and X-ray photoelectron spectra are measured by using MgK_α. The desorption peaks are observed in the temperature region where the van der Waals interactions are not considered. For the sort of sample and rare gas, the desorption profiles are different from each other. These characteristics does not depend on the evacuation time. After the exposure to rare gases, the C1s and valence band XPS spectra change from the original one. In the case of Ar, a large chemical shifts to the higher binding energy side are observed. These facts on the characteristic interaction of rare gases such as He, Ne, Ar, Kr and Xe is first report. New catalytic activities are also found to occur at the characteristic files of solid sites.
|
