Crystal structure and growth of carbon-silicon mixture film prepared by ion sputtering

Si (10-50%)-containing carbon (C-Si) films were prepared by ion sputtering of carbon and silicon carbide mixture pellets. The C-Si film was composed of a solid-solution phase of carbon and silicon with a diamond structure. The film showed a higher transparency than a simultaneously evaporated C-Si mixture film. Diamond crystals 100 nm in diameter were also produced by vacuum heating of C-Si film at 800°C. The infrared spectrum showed significant absorption features at 9.5 and 21μm, in contrast to the 11 and 12μm of SiC. The 21μm feature is one of the candidate unidentified infrared bands on the spectra of carbon-rich post-asymptotic giant branch stars.