Atomic-scale surface demixing in a eutectic liquid BiSn alloy.
Resonant x-ray reflectivity of the surface of the liquid phase of the Bi(43)Sn(57) eutectic alloy reveals atomic-scale demixing extending over three near-surface atomic layers. Because of the absence of an underlying atomic lattice which typically defines adsorption in crystalline alloys, studies of adsorption in liquid alloys provide unique insight on interatomic interactions at the surface. The observed composition modulation could be accounted for quantitatively by the Defay-Prigogine and Strohl-King multilayer extensions of the single-layer Gibbs model, revealing a near-surface domination of the attractive Bi-Sn interaction over the entropy.
Shpyrko
Oleg G
OG
Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA. oleg@xray.harvard.edu
Grigoriev
Alexei Yu
AY
Streitel
Reinhard
R
Pontoni
Diego
D
Pershan
Peter S
PS
Deutsch
Moshe
M
Ocko
Ben
B
Meron
Mati
M
Lin
Binhua
B