Structural analysis of carbon films deposited from argon- acetylene gas mixtures

Abstract

The amorphous carbon films were deposited on the stainless steel substrates at atmospheric pressure from argon-acetylene mixture by plasma jet chemical vapor deposition. The Ar/C2H2 gas volume ratio varied from 100:1 to 200:1, while the distance between plasma torch nozzle exit and the samples was 0.005÷0.02 m. Scanning electronic microscope analysis demonstrated that the surface roughness and growth rate of the films increases with decrease of Ar/C2H2 ratio. The hydrogen concentration falls from 27 at.% to 5 at.% with the decrease of the distance from 0.02 to 0.005 m. The increase of the Ar/C2H2 ratio from 100:1 to 200:1 slightly increases the hydrogen and oxygen concentration in the films. The Fourier transform infrared spectra demonstrated an existence of C and C=O sp2 bonds and presence of sp3 CH2-3 modes in coatings. The Raman spectroscopy indicated that the film prepared at Ar/C2H2 = 100:1 and 0.005 m has the highest sp3 C-C fraction. The coating deposited at 0.02 m has the highest fraction of sp3 CHx bonds. The hardness of the carbon films deposited at 0.005 m was in range of 7.1- 9.3 GPa. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/20569