Deposited carbon distributions on nickel film/oxide substrate systems

Distribution of deposited carbon at early stage is investigated by micro-Raman spectroscopy. Model samples consisting of nickel films sputtered on oxide substrates were used. Carbon deposition treatment was carried out for three nickel/oxide systems: Ni/YSZ (Yttria Stabilized Zirconia), Ni/ScSZ (Scandia Stabilized Zirconia), and Ni/GDC (Gadolinia doped ceria) at 873 K under dry 4.9% CH4/Ar gas. Significant carbon deposition was observed on the nickel surfaces for both Ni/YSZ and Ni/ScSZ. No carbon was observed on the nickel surfaces of Ni/GDC system. According to Raman spectra, the deposited carbon bonding state was similar between Ni/YSZ and Ni/ScSZ systems and it correspond to a graphitic phase.