Absorption and cathodoluminescence spectra have been obtained from synthetic diamonds which have been heated at temperatures between 1700 and 2400 C to produce various degrees of nitrogen aggregation. At the lower temperatures, a number of optical centers attributed to nitrogen in intermediate stages of aggregation are observed; at the highest temperatures, most of the nitrogen is present in the A-aggregate form with a small fraction in the B-aggregate form. The relative intensities of the H1b and Hlc absorption lines in the near-infrared spectral region around 2 microns provide a sensitive indication of the A- to B-nitrogen ratio. Although most of the nitrogen is present in aggregated form following these high-temperature treatments, the absorption and luminescence spectra are very different from those observed for natural type-Ia diamonds.
Journal of Physics D Applied Physics
- Pub Date:
- December 1985
- Absorption Spectra;
- Near Infrared Radiation;
- Spectral Energy Distribution;
- Solid-State Physics