Glow discharge optical emission spectrometry on the formation of thin oxide layers on the iron binary alloy surface

Glow discharge optical emission spectrometry (GDOS) has been used for characterizing thin oxide layers formed on iron-base binary alloys with aluminum, silicon, phosphorus, chromium, manganese, nickel and molybdenum by heating in air at 773 and 873 K. We focused on the enrichment of alloying elements in the thin oxide layers and substrates as well as the effect of alloying elements on the thickness of the oxide layers. It was found in the quantitative depth profiles that aluminum, silicon, phosphorus, chromium and nickel are enriched at the oxide/metal interface, while manganese is distributed to the oxide layer and molybdenum is observed neither at the oxide/metal interface nor in the oxide layer. It is also suggested that aluminum, silicon, chromium and molybdenum have a significant influence on the reduction in the thickness of the oxide layers, and the present results are in good agreement with structural data obtained by X-ray diffraction.