A. Galdikas et L. Pranevicius, Surface composition changes of ternary alloys in the non-steady state regime of preferential sputtering, NUCL INST B, 164, 2000, pp. 868-872
The phenomenon of experimentally observed non-monotonic time dependencies o
f the surface composition of alloys observed at sharp changes in parameters
of ion irradiation (energy, flux) is considered by a proposed phenomenolog
ical model. The ternary Ag-Pd-Au alloy samples of different bulk compositio
n were bombarded by Ar+ ions of 2 keV energy and then the ion energy was ab
ruptly changed from 2 to 5 keV. It is shown that the changes in surface com
position taking place at the time intervals before the steady state regime
of sputtering is reached are initiated by mass transport processes taking p
lace in the bulk of the solid. At the steady state regime the surface compo
sition is determined by the component sputtering yields and processes of se
gregation. The matrix-dependant sputtering yields are calculated by the pro
posed model. (C) 2000 Elsevier Science B.V. All rights reserved.