CRYSTALLIZATION ON CUZR AMORPHOUS ALLOY SURFACE - AN X-RAY PHOTOELECTRON-SPECTROSCOPY STUDY

Investigations of crystallization on the Cu30Zr70 amorphous alloy surface are carried out by differential scanning calorimetry (DSC) and X-ray photoelectron spectroscopy (XPS). The results show that the crystallization behavior on the surface of the sample is different from that in the bulk. The crystallization process may start from the surface and then propagate into the bulk. It is due mainly to the diffusion and segregation of Zr in the Cu30Zr70 sample toward the surface induced by oxygen and lattice strain during the annealing treatment. The oxide of Zr is observed on the surface, and by decomposition of the Zr3d spectra of the Cu30Zr70 sample, the presence of sub-oxide ZrO is established, their binding energy (3d5/2 peak) locates near 181 eV. It is formed due to the oxygen existing in the sample environment, the element Zr oxidizes and becomes strongly enriched on the surface.