Phase separation in argon/neon mixtures

The desorption behaviour of quench-condensed rare gas films has been investigated using high-frequency surface acoustic waves. Measurements on the binary mixture Argon(1-x)/Neon(x) have been carried out. For small and very large concentrations x(Ne) a behaviour is found, which indicates the existence of a substitutionally disordered solid. In contrast, for concentrations 0.25 < x(Ne) < 0.92 two discrete temperatures for Ne desorption exist. This indicates that for a wide range of concentration, quite surprisingly, two separate phases, one of pure Ne and the other of crystallites with either AB(2) or AB(3) structure, are formed. (C) 2002 Published by Elsevier Science B.V.