Acoustic studies of melting and freezing for mercury embedded into Vycor glass

Acoustic technique was used to study the melting and freezing phase transit ions of mercury embedded into Vycor glass. Both freezing and melting were f ound to be smeared and shifted noticeably to low temperatures compared to t he melting point of bulk mercury, the offset of melting occurred at 323 K. The liquid skin model which was developed to treat melting in isolated meta llic particles was used to explain the partly reversible character of melti ng for confined mercury and the difference between results obtained for lon gitudinal and transverse waves. Tile temperature dependence of the liquid s kin thickness was calculated. Freezing was suggested to be driven by nuclea tion processes. It was shown that for confined mercury there is no unambigu ous correspondend between pore sizes and temperatures of melting. (C) 2001 Published by Elsevier Science B.V.