Electron spectroscopy studies of doped and endohedrally doped fullerenes

Summary form only given. Electron spectroscopies have been used to study the crystal and electronic structure of the K-C/sub 60/, K-C/sub 70/ systems and of the endohedrally doped fullerene La@C/sub 82/. Electron energy loss studies yield information on the momentum dependence of the dielectric function, in particular on the dispersion of the charge carrier plasmon in K/sub 3/C/sub 60/. Photoemission core level analysis and vacuum distillation indicate equilibrium K/sub 1/C/sub 70/, K/sub 4/C/sub 70/ and K6C/sub 70/ phases at room temperature. A K/sub 3/C/sub 70/ phase has been found above 440K, which transforms into K/sub 1/C/sub 70/ and K/sub 4/C/sub 70/ at lower temperatures. None of the K/sub x/C/sub 70/ phases are metallic. Almost complete charge transfer of the 3 outermost valence electrons of La to the C/sub 82/ cage has been observed for La@C/sub 82/. These molecules form a nonmetallic solid which probably can be understood in terms of chemical bonding of the molecular radicals in the solid, which is consistent with a much higher sublimation temperature in comparison to pure C/sub 82/.