About cookies on this site Our websites require some cookies to function properly (required). In addition, other cookies may be used with your consent to analyze site usage, improve the user experience and for advertising. For more information, please review your options. By visiting our website, you agree to our processing of information as described in IBM’sprivacy statement. To provide a smooth navigation, your cookie preferences will be shared across the IBM web domains listed here.
Publication
Surface and Interface Analysis
Review
On the role of Gibbsian segregation in causing preferential sputtering
Abstract
It is well known that preferential sputtering with binary alloys correlates significantly with chemical binding, but only the sense and not the magnitude of the effect can be understood in these terms. It is argued here that the correlation is, in fact, an indirect one due to bombardment‐induced Gibbsian (or similar) segregation. The preferentially removed component is characterized by a composition profile consisting of a one atom‐layer‐thick spike at the surface; this is the depth from which most sputtered atoms originated so the spike must have near‐bulk composition. There is then a severely depleted subsurface region in accordance with Gibbsian segregation equilibrium (or an equivalent effect) and a final return to bulk composition. The reason for the marked correlation with chemical binding is that segregation is governed significantly more often by binding than by the alternatives of size, surface chemistry, an interstitial flux, or long‐range ordering. Copyright © 1985 Wiley Heyden Ltd.