Rb and Cs K-edge EXAFS spectra have been measured in the temperature range from 10 to 290 K, in order to investigate the temperature dependence of local structure around Rb+ and Cs+ ions in various alkali doped fullerenes. It has been found that the alkali metal ions in Rb3C60, K2RbC60 and Na2CsC60 occupy the center of the tetrahedral and octahedral sites of C60 crystals. The metal ion in the octahedral site exhibits a large fluctuation in comparison with that in the tetrahedral site. The increase in σ(2) of the t-site Rb-C for Rb3C60 has been observed around Tσ while the increase in σ(2) has not clearly been observed for the o-site Rb-C in K2RbC60. The local structure around Rb+ ion in non-superconducting alkali doped fullerene Rb6C60 has also been studied to compare with that in superconducting fullerenes.
ASJC Scopus subject areas
- Physics and Astronomy(all)