|Title||Glass transition in ultrathin films of amorphous solid water|
|Publication Type||Journal Article|
|Year of Publication||2012|
|Authors||Sepúlveda, A, Leon-Gutierrez, E, Gonzalez-Silveira, M, Rodríguez-Tinoco, C, Clavaguera-Mora, MT, Rodríguez-Viejo, J|
|Journal||The Journal of Chemical Physics|
|Keywords||Crystallization, Glass transitions, Heat capacity, Thin films, Water heating|
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.
|Short Title||The Journal of Chemical Physics 137, 244506 (2012)|