Multi-Peak Fitting Analysis of Visible Raman Spectra on DLC Coatings Deposited by Vacuum Arc

Abstract

The typical two-Gaussian fitting of Raman spectra is widely used in disordered and amorphous carbon. However, two-peak fitting method was not always suitable for all amorphous carbons, which made it important to choose appropriate fitting method for different carbon coatings. In this study the diamond-like carbon (DLC) coatings were deposited on steel (P2000) by a vacuum arc adjustable from anodic to cathodic operation mode. The ID/IG ratios of DLC coatings were investigated by visible Raman spectroscopy with multi-peak fitting analysis. It is found that for Raman spectra of DLC coatings deposited by vacuum arc four-peak Gaussian fitting is the most suitable method which is conducive to revealing fine structure of DLC films. Furthermore, by comparing with two-peak and three-peak fitting methods, the four-peak fitting method have lower ID/IG ratio. It is shown that the values of ID1/IG1 and I(D1+D2)/I(G1+G2) of four-peak Gaussian function are consistent nearly.