Corrosion behavior of nitrogen doped diamond-like carbon thin films in NaCl solutions

Nitrogen doped tetrahedral amorphous carbon (ta-C:N) thin films were grown on p-Si(1 1 1) substrates using filtered cathodic vacuum arc (FCVA) deposition by varying nitrogen flow rate. The effect of nitrogen flow rate on the corrosion performance of the films was investigated through potentiodynamic polarization and immersion tests in 0.6 M NaCl solutions. The polarization results showed that the corrosion resistance of the films dropped with increased nitrogen flow rate due to formation of more sp2 bonds. The immersion tests revealed that the pH value of the solutions had a significant effect on the corrosion behavior of the ta-C:N films.