Abstract
The influence of temperature and pressure conditions during high-pressure, high-temperature (HPHT) annealing on the dissociation of nitrogen aggregates is investigated, and special attention is paid to the influence of pressure. When PT conditions are above the diamond-graphite equilibrium line, an activation energy of 5.6 +/- 1.4 eV is calculated from the Arrhenius plot of the dissociation rate of A centres by assuming that the dissociation reaction of A centres follows first order kinetics. A second estimate for the binding energy of the A centres, derived from the equilibrium concentrations of A centres and C centres at three different temperatures, gives a value of 7.66 +/- 0.6 eV. The dissociation rate of A centres is enhanced by a factor of similar to10 when the PT point during the HPHT annealing is located in the graphite stable region of the carbon phase diagram. (C) 2002 Elsevier Science B.V. All rights reserved.
| Original language | English |
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| Pages (from-to) | 507 - 510 |
| Number of pages | 4 |
| Journal | DIAMOND AND RELATED MATERIALS |
| Volume | 12 |
| Issue number | 3-7 |
| Publication status | Published - Mar 2003 |
| Event | 13th European Conference on Diamond, Diamond-Like Materials, Carbon Nanotubes, Nitrides and Sililcon Carbide (Diamond 2002) - GRANADA, Spain Duration: 1 Jan 2003 → … |