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| 2. |
- Buga, Sergei G., et al.
(författare)
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Dissociation energy of 3D-polymeric C60 : Calorimetric study and structural analysis
- 2001
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Ingår i: Electronic Properties of Novel Materials - Science and Technology of Molecular Nanostructures. - Melville, NY : American Institute of Physics. - 0735400334 ; , s. 49-53
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Konferensbidrag (refereegranskat)abstract
- Annealing of 2D- and 3D-polymeric C[sub60] fullerene obtained under pressures of 9.5 and 12.5 GPa and temperatures of 670 and 770 K has been investigated by DSC in the range 240–640 K. An endothermal heat effect was observed with a peak maximum just below 540 K, a temperature characteristic for breakdown of (2+2) intermolecular links in dimers, 1D and 2D polymers. Exothermal effects, starting from 380 K, were observed for the first time in polymeric fullerenes. These effects are attributed to relaxation processes and to breakdown of other types of intermolecular bonds such as common four-sided rings and (3+3) interlinks.
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| 3. |
- Buga, Sergei G., et al.
(författare)
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DSC study of annealing and phase transformations of C60 and C70 polymerized under pressures in the range 9.5 - 13 GPa.
- 2002
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Ingår i: Journal of Physics and Chemistry of Solids. - : Elsevier B.V.. - 0022-3697 .- 1879-2553. ; 63:2, s. 331-343
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Tidskriftsartikel (refereegranskat)abstract
- C60 and C70 fullerenes polymerized under pressures between 9.5 and 13 GPa and temperatures between 670 and 1850 K were investigated by differential scanning calorimetry (DSC) in the range 240–640 K. Endothermal heat effects were observed with a peak maximum just below 540 K, a temperature characteristic for breakdown of (2+2) intermolecular links in dimers, 1D and 2D polymers. Exothermal effects, starting from 380 K, were observed for the first time in polymeric fullerenes. These effects are attributed to relaxation processes and to breakdown of other types of intermolecular bonds such as common four-sided rings and (3+3) interlinks.
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| 4. |
- Buga, Sergei G., et al.
(författare)
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Synthesis of superhard 3D-polymeric C60 fullerites from rhombohedral 2D-polymer by high-pressure-high-temperature treatment.
- 2003
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Ingår i: High Pressure Research vol. 23, issue 3. - London : Taylor & Francis. ; , s. 259-264
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Konferensbidrag (refereegranskat)abstract
- Rhombohedral C60 polymer was subjected to high-pressure-high-temperature treatment at P =13 GPa, T =620-1620 K. After quenching, crystalline and disordered structures with densities in the range of 2.1-2.9 g cm-1 were obtained. The structures of the samples have been investigated by powder X-ray diffraction and Raman scattering. DSC analysis showed a transformation of the polymeric structure into monomeric on annealing in the range 400-640 K. The temperature dependence of the electrical resistance of samples with disordered structure was measured in the range 2.5-300K. For different samples, the conductivity was proportional to T1/2, T3/2, T4 and exp(-1/T1/4).
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