Angular distributions of atoms sputtered from NiAl{110} and Ni{100}

Characterization of the surface film on Zr-based bulk metallic glass using X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM)

“…The Standard Electrode Potential is −1.66 V for the reaction Al 3+ + 3e − ↔ Al(s) [16], and −0.25 V for the reaction Ni 2+ + 2e − ↔ Ni(s) where (s) represents solid. Tan and King have studied the population, angular and time-of-flight mass spectra of Al and Ni neutral atoms sputtered from the surfaces of Ni(1 0 0) and NiAl(1 1 0) single crystals under a ultra high vacuum (UHV, the base pressure of chamber is 1.5 × 10 −9 mbar) [17][18][19][20] and found during the study that the NiAl(1 1 0) surface is easier to get oxidized than the Ni(1 0 0) surface. (The gas molecules in the UHV chamber consist mainly of H 2 and H 2 O, and the oxidation is due to the interaction of the Ni(1 0 0) and Ni(1 1 0) surfaces with H 2 O) We therefore believe that the reason why the NiAl(1 1 0) surface is easier to get oxidized than Ni(1 1 0) is the preferential (easier) oxidation of Al metal atoms in the NiAl alloy.…”