The homogeneous crystallization of water at low temperature is believed to occur through the direct nucleation of cubic (1,) and hexagonal (I-h) ices. Here, we provide evidence from molecular simulations that the nucleation of ice proceeds through the formation of a new metastable phase, which we name Ice 0. We find that Ice 0 is structurally similar to the supercooled liquid, and that on growth it gradually converts into a stacking of Ice I-c and I-h. We suggest that this mechanism provides a thermodynamic explanation for the location and pressure dependence of the homogeneous nucleation temperature, and that Ice 0 controls the homogeneous nucleation of low-pressure ices, acting as a precursor to crystallization in accordance with Ostwald's step rule of phases. Our findings show that metastable crystalline phases of water may play roles that have been largely overlooked.
|Titolo:||New metastable form of ice and its role in the homogeneous crystallization of water|
|Autori interni:||ROMANO, Flavio|
|Data di pubblicazione:||2014|
|Appare nelle tipologie:||2.1 Articolo su rivista |
File in questo prodotto:
|russo-nmat-2014.pdf||2.6 MB||Adobe PDF||Versione dell'editore||Riservato|