Nanocrystalline Diamond Film Produced by Argon Addition in the CH₄-H₂ Microwave CVD Plasmas

Diamond coatings on pure titanium substrates are of interest for tribological and biomedical implants. However, due to the different thermal expansion coefficients of the two materials, the complex nature of the interlayer formed during diamond deposition, and the difficulty in achieving very high nucleation density, it is hard to deposit adherent thin diamond layers on titanium. The aim of the present research was to successfully produce smooth and well adherent nanocrystalline diamond (NCD) film on a pure Ti substrate using the microwave plasma chemical vapor deposition (MWPCVD) method. The influence of Argon addition to CH4/H2 plasma on the crystallinity, morphology and growth of the diamond film deposited by MWPCVD was investigated using field emission scanning electron microscopy (FE-SEM), atomic force microscopy (AFM), Xray diffraction (XRD) and Raman spectroscopy.