Various types of endohedral fullerene complexes are known to date. The well known metallofullerenes are generally produced by arc-discharge method, but the use of such extremely drastic conditions is apparently not suitable for encapsulation of unstable molecules or gases. We recently succeeded in incorporation of a H 2 molecule or an Ar atom in 100% into a C 60 . In order to observe the endohedral gas molecule directly, the X-ray diffraction analysis using synchrotron radiation were carried out. We observed a gas molecule encapsulated in each fullerene cage using structure analysis and the maximum entropy method. These gas molecules are floating inside of the hollow cavities and are completely isolated from the outside

We developed a low-energy (100 eV) electron gun that uses the photoelectric eŠect, and demonstrated its capability for the study of electronic excitation processes at the surfaces of solids. A LaB 6 (100) single crystal was used as a photocathode and a laser diode (E photon ＝2.62 eV) was used as a light source. The electron gun was compatible with ultra-high vacuum (UHV) conditions due to its low outgassing. An energy width of 0.11 eV was obtained without an energy selector, and the maximum current was 38 nA. The energy width of the emitted electrons and the work function of the photocathode were estimated from the relation between the photoelectron energy distribution and the cathode temperature. Using the electron gun, we successfully observed the electron-stimulated desorption of metastable Ne atoms from a solid Ne surface.

Synopsis For the quantitative investigation of the potential sputtering process on the surface of noble gas solid, we have performed the coincidence measurement of the ions desorbed and projectiles scattered from solid Ne surfaces, due to 3 keV Ar6+ impacts at grazing incidence angles. The dependence of Ne n + desorption on the charge state of the scattered Ar projectiles is found.

We have developed a new experimental apparatus for performing coincidence measurements of the ions desorbed and projectiles scattered from the surfaces of noble gas solids by slow multiply charged ion impacts at grazing incidence angles. This simultaneously measures the desorbed ions' flight times and the scattered projectiles' charge states. We also conduct experiments on 6 keV Ar6+ impacts onto a solid Ne surface using the device.