Desorption Behavior of Quench-Condensed Argon-Neon Mixtures

The desorption behavior of quench-condensed rare gas films has been investigated using high frequency surface acoustic waves. Measurements of pure films of argon and neon and of the binary mixture Ar(1-c)/Ne(c) have been carried out. For small and very large neon concentration c(Ne) a behavior is found which indicates the existence of a substitutionally disordered solid. In contrast, in the wide range of concentration 0.25< c(Ne)< 0.92 two discrete temperatures for neon desorption exist. The data clearly indicate the occurrence of two separate phases, one of pure neon, the other of crystallites with either Ar(2)Ne or Ar(3)Ne structure.