The well-crystallized cubic boron nitride (c-BN) films have been prepared on polycrystalline Ni substrates using a hot filament assisted rf plasma chemical vapor deposition method. X-ray diffraction showed that high quality c-BN films had been deposited without hexagonal BN (h-BN) or amorphous BN codeposition. Both (111) and (100) faces were observed in scanning electron microscopy images. These results suggested that Ni had catalyst effects on the nucleation and the growth of c-BN phase and inhibited the formation of h-BN.
The effect of annealing temperatures on the optical-absorption edge of hydrogenated amorphous silicon-carbon alloys (a-SiC:H), prepared by the decomposition of a silane-methane gas mixture highly diluted with hydrogen, has been studied. A comparison of the absorption spectra of a-SiC:H films, obtained by re6ectance and transmittance measurements and by the constant-photocurrent method, is presented. The optical band gaps (Eg ) decrease and the widths of the band tails (Eo) increase with increasing annealing temperature. The low-energy absorption lines, in the dependence of the absorption coefficient on the photon energy for various annealing temperatures and in the dependence of absorption coefficient on the temperature for different isophoton energies, converge to a point. The higher the hydrogen content in the films, the larger the effects of annealing on the disorder in the sample structure. These results have been explained by use of structural-disorder models.
Fourier-transformation infrared spectroscopy (FTIR) was used to study C60 thin films which have been annealed for various times. The results show that the intermolecular interactions between C60 molecules in the films affect the vibrational modes. The 1428 cm−1 mode is the most sensitive mode to the interaction. A vibrational mode at about 669 cm−1 appears in the IR spectra of the films and increases with the annealing time; this mode represents the intermolecular interactions between the C60 molecules in the films. The peak position shift and the relative height of 1428 cm−1 mode increase with the increase of the 669 cm−1 mode peak height. The mechanism of the changes of vibrational modes has been discussed.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.