Electrodeposition of nanostructured diamond-like films by oxidation of lithium acetylide

Diamond-like carbon (DLC) films have been deposited by anodic oxidation of 4 M solution of lithium acetylide in dimethylsulfoxide on the surface of stainless steel or nickel electrode at room temperature and moderate anodic current densities (0.2-2.0 mA/cm(2)) in the range of electrode potentials 0.3-2.5 V (vs. sat. Ag\AgCl reference electrode). Electrodeposited DLC coatings represented complete and optically transparent films of a thickness 50-100 nm having dark island inclusions with a diameter 0.8-5.0 gm. The concentration and average size of these particles increased with the prolongation of deposition time. Micro-Raman spectra obtained by the focusing of laser beam onto these dark inclusions are characterized by a broad peak centered at 1500 cm(-1) and weak peak at 1200 cm(-1). With a defocused laser beam, there appear two well-distinguished peaks on the integrated Raman spectra-at 1530 and 1130 cm(-1). Analysis of Raman spectra with the use of a Breit-Wigner-Fano lineshape and spectrum deconvolution indicates that the electrodeposited films consist of diamond-like nanostructured carbon with a high content (70-80%) of sp(3) phase. (C) 2003 Elsevier Science B.V. All rights reserved.