Electron beam induced oxidation of surfaces of Ni3Al-base alloys

This letter concentrates on phenomena of the electron beam (e-beam) induced oxidation of surfaces of Ni3Al-base alloys. In particular it is shown that an e-beam may contribute substantially to the oxidation behavior of polycr ystalline Ni3Al and Ni3Al-B surfaces during Auger analysis at room temperat ure. Upon e-beam exposure oxidation occurs rapidly, even though any regime of oxygen chemisorption is absent. Auger peak-to-peak oxygen curves for Ni3 Al(-B) surfaces appear to support the model by Li et al. [J. Vac. Sci. Tech nol. A 13(1995) 1574] based on the premise that the e-beam creates addition al nucleation sites for oxidation. In contrast, for pure Ni containing B in solid solution a chemisorption regime is indeed present which is then foll owed by a rapid formation of oxides that saturates quickly at a time scale similar to that of the Ni3Al-base systems. Although Al does not participate in the e-beam induced oxidation, the cross-sections for creation of oxide sites are found to be drastically higher than those of Ni/B and pure Ni. (C ) 2001 Elsevier Science B.V. All rights reserved.