FULLERENE SINGLE-CRYSTALS - STRUCTURE AND ELECTRONIC-PROPERTIES

This work covers an advanced investigation of the single crystal growt h process for fullerenic materials and the contribution of Raman and I R spectroscopy to the understanding of the fee high temperature rotor phase and the low temperature sc ratchet phase of pristine C-60. In ad dition substantial research contributions to the understanding of alka li metal doped fullerenes are presented.Alkali metal doped crystals ar e studied with particular attention to the line broadening in the supe rconducting A(3)C(60) phase and to the phases with stoichiometry A(1)C (60). For the former electron-phonon coupling constants could be deter mined for all fivefold degenerated gerade modes and a total coupling s trenght of lambda = 0.90 was found. For the latter the different exper imental conditions for obtaining the phase separated intermediate stat e or alternatively the orthorhombic polymeric state are analysed. Vibr ational spectra for the polymeric state obtained from phototransformat ion and from mono alkali metal doping are found to be characteristical ly different, mainly with respect to the intensity of the Raman or IR response. Finally, research results obtained from the single crystals by various other techniques Like thermal expansion or low frequency el astic deformation are summarized.