Structure and corrosion behavior of platinum/ruthenium/nitrogen doped diamondlike carbon thin films

Platinum/ruthenium/nitrogen doped diamondlike carbon (PtRuN-DLC) thin films were deposited on p-Si (100) substrates with dc magnetron cosputtering by varying the dc power applied to a Pt50Ru50 target to investigate the effect of Pt and Ru incorporation in the films on the bonding structure, adhesion strength, surface morphology, and corrosion behavior of the films by means of X-ray photoelectron spectroscopy, micro-Raman spectroscopy, microscratch test, atomic force microscopy, scanning electron microscopy, and potentiodynamic polarization test. It was found that the incorporation of Pt and Ru in the N-DLC films improved the corrosion resistance of the films in a 0.1M NaCl solution at lower polarization potentials though more sp(2) bonds were formed in the films. However, the films with higher Pt and Ru contents degraded earlier than the ones with lower Pt and Ru contents at higher polarization potentials.