Study of the Behaviors of Diamond-like Carbon Films Prepared by Middle Frequency Pulsed Unbalanced Magnetron Sputtering Technique at Different Gas Pressures

摘要

Diamond-like carbon (DLC) films were prepared by using the middle frequency pulsed unbalanced magnetron sputtering technique (MFPUMST) at different Ar pressures. The structural and the mechanical properties of the films were characterized using Raman spectra and nano-indentation tests. The Raman spectra showed that the sp3 fraction in the DLC films decreases with increasing gas pressure from 0.27 to 1.60 Pa. The mechanical properties, like the nanohardness and the elastic recovery, for these films under different gas pressures showed the same tendency in that the nano-hardness and the elastic recovery decreased with increasing gas pressure from 0.27 to 1.60 Pa. The variations in the nano-hardness and the elastic recovery could be interpreted by using the different sp3 fraction in the prepared DLC films. Also, the gas pressure had a strong influence on the bonding properties of the deposited DLC films. The mechanism for the effect of gas pressure on the sp3 fraction is discussed in this paper.