X-ray photoelectron spectroscopy analysis of SS304 samples treated with argon glow discharge conditioning

Abstract

Samples of SS304 material were heated in air 220°C for 7 h to increase the impurity content of the sample surface. These were treated with argon glow discharge conditioning (GDC) at 0.04 and 0.004 mbar. The untreated and treated samples were later analysed using X-ray photoelectron spectroscopy (XPS). The results indicate the presence of Fe-oxides and carbon on the surface of the untreated sample. Cr and Ni are absent on this surface. On the sample surfaces treated with GDC at 0.04 and 0.004 mbar, 0 1s and C 1s do not shift from their initial binding energy ( BE) positions. However, the Fe 2 p peak shifts to a lower ( BE) position in both cases. This indicates the reduction of Fe oxides due to GDC. On the sample surface treated at 0.04 mbar GDC, the Ni 2 p and Cr 2 p peaks appear at BE positions corresponding to their oxide states. On the sample surface treated with GDC at 0.004 mbar, these peaks shift to lower BE positions characteristic of their metallic states. The relative concentration of carbon decreases with a decrease in pressure. In addition, the reduction in the relative concentration of oxygen is substantial in low pressure treatment as compared with its marginal reduction in high pressure treatment.