| Title: |
Topology and Electronic Structure of Onion-Like Carbon and Graphite/Diamond Nanocomposites |
| Authors: |
Bulusheva, Lyubov G.; Okotrub, Alexander V.; Kuznetsov, Vladimir L.; Chuvilin, Andrew L.; Butenko, Yuriy V.; Heggie, Malcolm I. |
| Source: |
MRS Proceedings ; volume 703 ; ISSN 0272-9172 1946-4274 |
| Publisher Information: |
Springer Science and Business Media LLC |
| Publication Year: |
2001 |
| Description: |
Annealing of nanodiamond at moderate temperature makes it possible to produce structures being intermediate in the carbon transformation from sp 3 - to sp 2 -state (graphite/diamond nanocomposites) and onion-like carbon (OLC). Electron microscopy shows such structures involve cage shells with spacing close to graphite. X-ray emission spectroscopy has been applied to examine the electronic structure of OLC and graphite/diamond nanocomposites. The CKα-spectra of OLC produced in the temperature range of 1600-1900 K were found to be markedly different from the spectrum of particles formed at 2140 K and characterized by better ordering of graphitic shells. The latter spectrum was shown to be very similar to the CKα-spectrum of polycrystalline graphite, while the former ones exhibited a significant increase of high-energy maximum that might be caused by the holed defect structure of graphitic networks forming at the intermediate annealing temperatures. To interpret experimental spectra, the quantum-chemical semiempirical AM1 calculation of icosahedral C 540 cage and that with holed defects was carried out. The lack of at least 22% atoms in an internal carbon cage was found to be essential to provide an increase of density of high-energy electronic states similar to that observed in the spectrum of OLC produced at 1900 K. |
| Document Type: |
article in journal/newspaper |
| Language: |
English |
| DOI: |
10.1557/proc-703-v9.22 |
| Availability: |
http://dx.doi.org/10.1557/proc-703-v9.22; https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S1946427400593312 |
| Rights: |
https://www.cambridge.org/core/terms |
| Accession Number: |
edsbas.571F18D8 |
| Database: |
BASE |