Defects in single crystal diamond grown by chemical vapour deposition (SC-CVD) have been studied using electron paramagnetic resonance (EPR) and optical techniques. Annealing studies in the temperature range of 900 - 1600°C have been performed and the changes in EPR and Fourier transform infrared (FTIR) spectra for nitrogen doped SC-CVD have been documented. It has been possible to model the annealing behaviour of several hydrogen related defects and the associated kinetics and annealing parameters have been determined. Previously unreported optical absorption lines have been detected in the as-grown and annealed nitrogen doped samples. FTIR spectroscopy has been performed in conjunction with an applied uniaxial-stress to investigate hydrogen related absorption features in diamond. Several absorption lines have shown to shift and split under the application of uniaxial-stress and the symmetry and stress-splitting parameters for these defects have been determined. Models for the defects responsible are proposed. The mid-infrared absorption line at 3123 cm-1 is suggested to originate from a C-H stretch mode at the paramagnetic negative nitrogen-vacancy-hydrogen complex. For a 3123 cm-1 absorption line with a Lorentz linewidth of 3.8(2) cm-1, 1 cm-1 of absorption at 3123 cm-1 corresponds to 25(10) ppm of NVH- centres. A previously unreported paramagnetic defect has been detected and is given the label WAR1. It has an S = 1 ground state and a pseudo-C3v symmetry; the g and D spin Hamiltonian parameters have been determined and suggest that the defect is vacancy related.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:490402 |
| Date | January 2007 |
| Creators | Cruddace, Robin |
| Publisher | University of Warwick |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://wrap.warwick.ac.uk/2964/ |
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