title: Characterisation of diamond coatings with different morphologies by Raman spectroscopy using various laser wavelengths.
abstract: Since the beginning of low-pressure diamond synthesis, Raman spectroscopy has been widely used to identify and characterise the quality of diamonds. The diamond crystal is characterised by a Raman peak at about 1,332 cm(-1). Other peaks are associated with miscellaneous carbon structures, e.g. graphite and amorphous phases. In recent years, both well-faceted crystalline diamonds and nanocrystalline and ultrananocrystalline diamonds have been investigated. For these fine-grained materials, the diamond peak at 1,332 cm(-1) disappears and the intensities of peaks at other wavelengths increase. To study the influence of the Raman laser wavelength, three lasers were used (472.681 nm, blue; 532.1 nm, green; 632.81 nm, red). For well-faceted diamonds, the Raman spectra with blue and green laser light were similar. A shift of the peak maxima and different intensities were observed. With use of the red laser, a strong luminescence peak and low peak intensities for the various carbon-related peaks occurred. When the diamond morphology changes from well-faceted to fine-grained ballas diamond, the spectra are similar for all three lasers.
authors.affiliation: Institute of Chemical Technologies and Analytics, University of Technology Vienna, Getreidemarkt 9/164-CT, 1060, Vienna, Austria.
authors.forename: Moritz
authors.initials: M
authors.lastname: Rudigier
authors.forename: Roland
authors.initials: R
authors.lastname: Haubner