Surface oxidation of amorphous Zr65Cu17.5Ni10Al7.5 and Zr46.75Ti8.25Cu7.5Ni10Be27.5

The initial oxidation and the native oxidation of the amorphous alloys Zr65Cu17.5Ni10Al7.5 (henceforth, called the Inoue alloy) and Zr46.75Ti8.25Cu7.5Ni10Be27.5 (Vitreloy 4 or V4) at room temperature were studied by X-ray photoelectron spectroscopy (XPS). The XPS analysis of the oxide films showed that the major constituent was Zr(IV) oxide, possibly as ZrO2 along with small amounts of the oxides of Ti, Be (in the alloy V4) and of Al (in Inoue alloy in the native oxide case) while Cu and Ni in both the alloys were present in their metallic forms only. The results are explained using the heat of formation data and the diffusion behaviour of the alloying elements.