ABSTRACT
Figure 5 shows the micro-Raman spectra at various positions on the cross section of the diamond coated specimen prepared with CVD treatment time of 30 h. In the spectra of positions 0 and © within the diamond film, one can see the typical diamond peaks at 1333 cm -1 and broad peaks corresponding to a small amount of amorphous carbon around 1500 cm-1 . Analogous peaks can be confirmed at position © near the interface in the substrate side, which verifies the anchored deposition of diamond into the micropores. Only a weak diamond peak can be observed at position 0 , which is located at about 10 μτη inside from the interface. At position © about 30 /xm inside from the substrate, a broad peak of DLC, which shifts slightly to a higher wavenumber, is seen, as well as the silicon nitride peaks in the wavenumber range lower than 1 0 0 0 cm - 1 (the spectrum of silicon nitride at far inside of the substrate is shown in (§)). It is noted that no peak corresponding to silicon carbide is observed in any of the spectra. Therefore, the results suggest
Figure 4. X-ray diffraction patterns of diamond coated specimens with CVD treatment times, (a) S13N4 sintered substrate untreated, (b) 2 h, (c) 10 h, (d) 20 h, (e) 30 h.
