Abstract
In this work we report X-ray scattering studies of the Cu 3Au(001) surface for temperatures above the bulk order-disorder transition temperature T 0=390°C. The temperature dependence of the asymptotic Bragg tails normal to the surface gives direct evidence for an oscillatory, exponentially damped Au segregation profile. It turns out that the depth range (λ) of this surface segregation phenomenon is governed by the bulk correlation length ξ b and, thus, depends sensitively upon the temperature, in particular, we find that λ∝( T— T sp) − v upon approaching the ordering spinodal temperature T sp with v=0.49. The inplan of the asymptotic Bragg tails exhibits a broadening which changes characteristically with the normal momentum transfer L An intimate coupling between the terrace structure and the lateral coherence of the surface segregation profiles is found. First experimental results from experiments performed at the ESRF are presented which disclose surface segregation-related diffraction features in higher Brillouin zones normal to the surface. The sensitivity of this X-ray probe to details of the surface segregation profile is discussed and the experimental limits are indicated.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
