Glass transition and crystallization dynamics of thin CCl(2)F(2) films deposited on Ni(111), graphite, and water-ice films.
The glass-liquid transition and crystallization of thin CCl(2)F(2) films, as well as the influence of substrates on the phase transition of a monolayer, have been investigated using temperature-programmed time-of-flight secondary ion mass spectrometry. The multilayer films of CCl(2)F(2) dewet a Ni(111) substrate abruptly at 57 K, which is explainable as immediate crystallization of supercooled liquid. The morphology of the crystalline CCl(2)F(2) film changes at 85 K; the molecules permeate through porous D(2)O films at temperatures higher than 70 K. These behaviors can be explained as the evolution of a second liquid or premelting of crystallites. The monolayer of CCl(2)F(2) formed on graphite undergoes a phase transition similar to that of the multilayer films, whereas the phase transition is quenched for the monolayer formed on the Ni(111) substrate. The phase transition of the CCl(2)F(2) monolayer formed on the D(2)O film is influenced by crystallinity, thickness, and morphology of the latter.
Souda
Ryutaro
R
International Center for Materials Nanoarchitectonics, National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan. souda.ryutaro@nims.go.jp