Articles
  • Tailoring mechanical properties and wettability of nanocrystalline diamond films by control of sp(2)/sp(3) bonding ratio
  • Jong Cheon Parka, Ok Geun Jeonga, Sungu Hwangb, Hee Soo Leec, Tae Gyu Kimd, Jin Kon Kimd and Hyun Chod*
  • a Department of Nano Fusion Technology, Pusan National University, Miryang, Korea b Department of Applied Nanoscience, Pusan National University, Miryang, Korea c School of Materials Science & Engineering, Pusan National University, Busan, Korea d Department of Nanomechatronics Engineering, Pusan National University, Miryang, Korea
Abstract
The ratio of sp(2)/sp(3) bonded carbon in nanocrystalline diamond (NCD) films was controlled by Ar addition to the CH4/H-2 mixtures and the effect of the sp(2)/sp(3) ratio on the mechanical/tribological properties and wettability was examined. Raman spectroscopy and XPS measurements revealed that Ar addition up to 45 sccm increases the sp(2)/sp(3) ratio and induces transition to NCD. Tribological properties such as friction coefficient and wear rate of the NCD film showed a strong dependence on the sp(2)/sp(3) bonded carbon ratio while hardness of the NCD films found to be closely related to the sp(3) bond fraction rather than the sp(2)/sp(3) ratio. Wettability of the NCD films grown in the CH4/H-2/Ar microwave plasmas found to be insensitive to the sp(2)/sp(3) ratio due to the non-negligible amount of hydrogen on the surfaces.

Keywords: Nanocrystalline diamond film; sp(2)/sp(3) ratio; Ar addition; Hardness; Friction coefficient; Wettability

This Article

  • 2014; 15(6): 549-554

    Published on Dec 31, 2014

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