| Autor: |
Davydov, V. A., Kashevarova, L. S., Rakhmanina, A. V., Agafonov, V., Allouchi, H., Ceolin, R., Dzyabchenko, A. V., Senyavin, V. M., Szwarc, H., Tanaka, T., Komatsu, K. |
| Zdroj: |
The Journal of Physical Chemistry - Part B; March 18, 1999, Vol. 103 Issue: 11 p1800-1804, 5p |
| Abstrakt: |
The high-pressure states of C60 fullerene corresponding to the 1.5 GPa isobaric section of its p,T diagram in the 293−1073 K temperature range were investigated by X-ray diffraction and IR and Raman spectroscopies. It was shown that increasing the treatment temperature of C60 at quasihydrostatic pressure changes the nature of the polymerization products. The IR and Raman spectra of the high-pressure materials obtained at 423 K are similar to the spectra of the dumb-bell-shaped C60 dimer synthesized in a solid-state mechanochemical reaction of C60 with potassium cyanide by Wang et al.1 It can be concluded that this dumb-bell-shaped dimer is the main structural unit forming the low-pressure polymerization product. So, on further temperature increase, the dimer phase becomes unstable and transforms into the low-pressure orthorhombic polymerized phase of C60 which, in turn, transforms into the tetragonal polymerized phase at temperatures above ~723 K. Depolymerization of the polymerized phases at temperatures above ~900 K results in the formation of the monomeric fcc phase of C60 fullerene, which agrees with the experimental data determined previously by Bashkin et al.2 |
| Databáze: |
Supplemental Index |
| Externí odkaz: |
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