Glass transition in ultrathin films of amorphous solid water

TitleGlass transition in ultrathin films of amorphous solid water
Publication TypeJournal Article
Year of Publication2012
AuthorsSepúlveda, A, Leon-Gutierrez, E, Gonzalez-Silveira, M, Rodríguez-Tinoco, C, Clavaguera-Mora, MT, Rodríguez-Viejo, J
JournalThe Journal of Chemical Physics
Volume137
Start Page244506
KeywordsCrystallization, Glass transitions, Heat capacity, Thin films, Water heating
Abstract

Nanocalorimetry at ultrafast heating rates is used to investigate the glass transition of nanometer thick films of metastable amorphous solid watergrown by vapor deposition in an ultrahigh vacuum environment. Apparent heat capacity curves exhibit characteristic features depending on the deposition temperature. While filmsgrown at T ≥ 155 K are completely crystallized, those deposited at 90 K show a relaxation exotherm prior to crystallization.Filmsgrown between 135 and 140 K and subsequently cooled down to 90 K reveal a clear endothermic feature before crystallization, which is compatible with a glass-to-liquid transition. The onset temperature is located at 174 K at a heating rate of 2.4 × 104 K/s and is independent of film thickness in the range of 16–150 nm. Comparison of our data with other calorimetric measurements at various heating rates suggests that water is a strong glass former in the deeply supercooled state.

URLhttp://link.aip.org/link/doi/10.1063/1.4771964
DOI10.1063/1.4771964
Short TitleThe Journal of Chemical Physics 137, 244506 (2012)
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