In this paper we deal with the investigation of the thin diamond-like layers (DLC) manufactured on magnesium alloys (AZ31) using Plasma Activated Chemical Vapour Deposition (PACVD) method. Raman spectroscopy investigation has been carried out for determining both layer composition and fraction of the diamond-like structure in the layers. The Raman spectroscopy is recognized as the main tool used for surveying of the allotropic content of the carbon layers. It is imposed by the necessity of the distinction not among the different chemical elements but among different bonds of the same chemical element-carbon, or alternatively-among different bonds of carbon with a few other chemical elements-especially hydrogen. During the Raman spectra analysis, both qualitative and quantitative analysis are performed, which is essential for the use of the carbon coatings in the broad range of mechanical technologies. A tool used in these investigations is Voigt peak profile based on Faddeeva function, allowing a very precise comparison of spectra with elimination of specificity of measurement equipment.
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