Nitrogen-Induced Degradation of Corrosion Resistance of Platinum/Ruthenium/Nitrogen-Doped Diamond-like Carbon Thin Films

An influence of nitrogen incorporation on the chemical composition, bonding structure, surface morphology and activity, adhesion strength, and corrosion resistance of platinum/ruthenium/nitrogen-doped diamond-like carbon PtRuN-DLC thin films deposited on conductive p-Si 100 substrates using dc magnetron sputtering deposition was investigated using X-ray photoelectron spectroscopy, micro-Raman spectroscopy, atomic force microscopy, sessile liquid drop method, microscratch test, potentiodynamic polarization test, and electrochemical impedance spectroscopy in terms of nitrogen flow rate. The sp2 sites in the PtRuN-DLC films increased with increased nitrogen flow rate, which was confirmed by increased C sp2/C sp3, N sp2/N sp3, and ID/IG ratios. The experimental results indicated that the decreased corrosion resistance of the PtRuN-DLC films in a 0.1 M NaCl solution with increased nitrogen flow rate was due to the changes in the chemical composition, bonding structure, porosity level, surface morphology and activity, and adhesion strength of the films associated with nitrogen incorporation. © 2010 The Electrochemical Society. DOI: 10.1149/1.3428724 All rights reserved.