Surface Crystallization in a Liquid AuSi Alloy Shpyrko, Oleg G; Streitel, Reinhard; Balagurusamy, Venkatachalapathy S.K ...
Science (American Association for the Advancement of Science),
07/2006, Volume:
313, Issue:
5783
Journal Article
Peer reviewed
Open access
X-ray measurements reveal a crystalline monolayer at the surface of the eutectic liquid Au₈₂Si₁₈, at temperatures above the alloy's melting point. Surface-induced atomic layering, the hallmark of ...liquid metals, is also found below the crystalline monolayer. The layering depth, however, is threefold greater than that of all liquid metals studied to date. The crystallinity of the surface monolayer is notable, considering that AuSi does not form stable bulk crystalline phases at any concentration and temperature and that no crystalline surface phase has been detected thus far in any pure liquid metal or nondilute alloy. These results are discussed in relation to recently suggested models of amorphous alloys.
Anomalous layering at the liquid sn surface SHPYRKO, Oleg G; GRIGORIEV, Alexei Yu; STEIMER, Christoph ...
Physical review. B, Condensed matter and materials physics,
12/2004, Volume:
70, Issue:
22
Journal Article
Peer reviewed
Open access
X-ray reflectivity measurements on the free surface of liquid Sn are presented. They exhibit the high-angle peak, indicative of surface-induced layering, also found for other pure liquid metals (Hg, ...Ga, and In). However, a low-angle shoulder, not hitherto observed for any pure liquid metal, is also found, indicating the presence of a high-density surface layer. Fluorescence and resonant reflectivity measurements rule out the assignment of this layer to surface segregation of impurities. The reflectivity is modeled well by a 10% contraction of the spacing between the first and second atomic surface layers, relative to that of subsequent layers. Possible reasons for this are discussed.
Science 313, 77 (2006) X-ray measurements reveal a crystalline monolayer at the surface of the
eutectic liquid Au_{82}Si_{18}, at temperatures above the alloy's melting
point. Surface-induced atomic ...layering, the hallmark of liquid metals, is also
found below the crystalline monolayer. The layering depth, however, is
threefold greater than that of all liquid metals studied to date. The
crystallinity of the surface monolayer is notable, considering that AuSi does
not form stable bulk crystalline phases at any concentration and temperature
and that no crystalline surface phase has been detected thus far in any pure
liquid metal or nondilute alloy. These results are discussed in relation to
recently suggested models of amorphous alloys.
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.
X-ray measurements reveal a crystalline monolayer at the surface of the eutectic liquid Au_{82}Si_{18}, at temperatures above the alloy's melting point. Surface-induced atomic layering, the hallmark ...of liquid metals, is also found below the crystalline monolayer. The layering depth, however, is threefold greater than that of all liquid metals studied to date. The crystallinity of the surface monolayer is notable, considering that AuSi does not form stable bulk crystalline phases at any concentration and temperature and that no crystalline surface phase has been detected thus far in any pure liquid metal or nondilute alloy. These results are discussed in relation to recently suggested models of amorphous alloys.
PDF
