The IR absorption in polycrystalline diamond films deposited in oxygen-acetylene flames was characterized using the Fourier transform IR spectroscopy (FTIR). The one-phonon absorption coefficient in the region from 7 to 12 μm that is related to extrinsic defects in the diamond films shows a strong dependence on the flame conditions as well as the substrate temperature. A high degree of diamond crystalline perfection, as judged from the undetectable one-phonon absorption, is achieved under the optimized deposition conditions for our flame set-up. This is further supported by the sharp Raman peak at 1332 cm-1 as well as the high purity in crystal orientation according to the X-ray diffraction pattern measured for the high quality diamond films. Optimal deposition conditions produce diamond films with a lower degree of secondary nucleation than is found in the lower quality diamond deposits.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Surfaces and Interfaces
- Surfaces, Coatings and Films
- Metals and Alloys
- Materials Chemistry