Berlin 2012 – scientific programme

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MM: Fachverband Metall- und Materialphysik

MM 25: Microstructure and Phase Transformations III

MM 25.1: Talk

Tuesday, March 27, 2012, 11:45–12:00, H 0106

Continuous freezing and delayering of argon in nanopores — •Klaus Schappert and Rolf Pelster — Universität des Saarlandes, FR 7.2 Experimentalphysik, Campus Geb. E2.6, 66123 Saarbrücken, Germany

We investigate the freezing behavior of argon in nanoporous Vycor glass. The freezing temperature of substances adsorbed in nanopores is lowered in comparison to bulk. Bulk argon freezes at 84 K, whereas argon filled in Vycor glass seems to freeze only at about 75-76 K. However, the first few adsorbed layers of argon will not freeze at that temperature and remain in a liquid-like condition. We show that both the first and the second argon layer freeze continuously over a broad temperature range of at least 40 K. These layers completely freeze only far below the bulk freezing temperature, i.e. around 20 K. Whereas those two adsorbed layers remain stable during cooling, the third one becomes unstable around 66 K, rearranges, and solid capillary condensate is formed (delayering transition) [1].

[1] Klaus Schappert and Rolf Pelster, Phys. Rev. B 83, 184110 (2011)