Electrodeposition of diamondlike carbon films on nickel substrates

Diamondlike carbon (DLC) films were electrodeposited on nickel substrates from a solution of acetylene in liquid ammonia at low temperature and low potential using a three-electrode cell. Raman spectra showed a shoulder D peak at 1365 cm−1 and a broad G peak at 1558 cm−1 for the films, indicating an sp3 and sp2 carbon mixture. The presence of a 1230 cm−1 peak also indicated some four-fold-coordinated bonds of microcrystalline diamond. Fitting of the peaks in the Raman spectra specified the electrodeposited films were hydrogenated amorphous alloys, a-C:H. X-ray photoelectron spectra also pointed to the films containing a mixture of sp3 and sp2 carbon. Fourier transform infrared spectra of the electrodeposited films had C-H stretching vibrations, which is consistent with hydrogenated DLC films.