On the Existence of Transition-Metal Fullerides: Deposition and Characterization of TixC60
1998 (English)In: Chemistry of Materials, Vol. 10, no 4, 1184-1190 p.Article in journal (Refereed) Published
Titanium fulleride films (TixC60) were prepared by coevaporating Ti and C60 onto moderately heated substrates (~100 C) in an ultrahigh vacuum system. The TixC60 films were all amorphous according to X-ray diffraction and exhibited a gray, metallic luster different from the brown color of pristine C60. The compound also appeared to be metallic or semiconducting as no charging was observed in X-ray photoelectron spectroscopy (XPS) in contrast to analyses of pure C60. XPS of the films showed a maximum titanium content of about 5.3-5.5 at. % (Ti~3.5C60). For higher titanium contents, carbide formation was observed. The XPS analyses also showed binding energy shifts and line broadening effects consistent with the formation of chemical bonds between Ti and C60. Raman spectroscopy showed a softening of the Ag(2) mode upon Ti incorporation (-4 cm-1/Ti atom) which is consistent with a partial charge transfer from Ti to C60. The TixC60 films oxidized immediately upon air exposure. However, XPS and Raman spectroscopy show persistent differences from pristine C60 which might indicate that another phase, TixOyC60, is formed upon oxidation.
Place, publisher, year, edition, pages
1998. Vol. 10, no 4, 1184-1190 p.
IdentifiersURN: urn:nbn:se:uu:diva-21055DOI: doi:10.1021/cm9707871OAI: oai:DiVA.org:uu-21055DiVA: diva2:48828