Effects of surface cleaning on oxidation of NiAl(1Â 1Â 0)

The effects of Ar+ ion sputtering on the surface of NiAl(1 1 0) and its oxidation behaviors were investigated using XPS and LEED. The surface roughness increased and the surface aluminium concentration decreased after several times of cleaning and oxidation of the NiAl(1 1 0) surface. This surface was shown to be less reactive under 1020 K oxidation but more reactive under 500 K than the first-cleaned NiAl(1 1 0) surface. After heating the samples with oxide over-layer to about 1320 K for about 15 min, the oxide over-layer was completely disappeared and a clean NiAl(1 1 0) surface was obtained. This result provided a new way to clean the NiAl(1 1 0) surface.