Mechanism of anisotropic surface self-diffusivity at the prismatic ice-vapor interface

0449079 - ÚOCHB 2016 RIV GB eng J - Článek v odborném periodiku
Gladich, I. - Oswald, A. - Bowens, N. - Naatz, S. - Rowe, P. - Roeselová, Martina - Neshyba, S.
Mechanism of anisotropic surface self-diffusivity at the prismatic ice-vapor interface.
Physical Chemistry Chemical Physics. Roč. 17, č. 35 (2015), s. 22947-22958. ISSN 1463-9076. E-ISSN 1463-9084
Grant CEP: GA ČR GA13-06181S
Institucionální podpora: RVO:61388963
Klíčová slova: molecular dynamics simulations * water models * melting point
Kód oboru RIV: CF - Fyzikální chemie a teoretická chemie
Impakt faktor: 4.449, rok: 2015

Predictive theoretical models for mesoscopic roughening of ice require improved understanding of attachment kinetics occurring at the ice-vapor interface. Here, we use classical molecular dynamics to explore the generality and mechanics of a transition from anisotropic to isotropic self-diffusivity on exposed prismatic surfaces. We find that self-diffusion parallel to the crystallographic a-axis is favored over the c-axis at sub-melt temperatures below about -35 degrees C, for three different representations of the water-water intermolecular potential. In the low-temperature anisotropic regime, diffusion results from interstitial admolecules encountering entropically distinct barriers to diffusion in the two in-plane directions. At higher temperatures, isotropic self-diffusion occurring deeper within the quasi-liquid layer becomes the dominant mechanism, owing to its larger energy of activation.
Trvalý link: http://hdl.handle.net/11104/0250710