Prof. Yun-Hee Lee [KRISS, South Korea]

Title: Anomalous growth transition of an ice crystal under fast compression

Time: 14:45 ~ 15:00, 16th July

Place: Conference room 410, HPSTAR (Shanghai)

Host: DuckYoung Kim

Polycom: 02120004

Abstract:

Crystal growth is usually governed by the interplay between thermodynamic driving force and microscopic kinetics at crystal-liquid interface. The interface interplay and resulting crystal morphology have been studied a lot under equilibrium condition, but not non-equilibrium condition which is important to investigate the formation of materials in interior of the earth, planets and meteorite impact.

Here, we study crystal growth of ice VI phase with compression rate using dynamic diamond anvil cell (dDAC) that can freely vary compression rate from 0.01 GPa/s to more than 1 TPa/s and thus can instantaneously generate large driving force. When fast compression is done for ice and water co-existing system, the ice crystal shows a dramatic morphology change of faceting, corners protrusion, concave edges and then fast growth of 2-d crystal emanated from 3-d crystal, which is entirely different with the monotonic facet growth under slow compression. We recognize that the anomalously fast growth starts from crystal edges rather than its corners and also measure significant supercompression despite of the presence of an ice crystal in liquid water with fast compression. In order to understand these phenomena under dynamic compression we propose a possible scenario for physical situation of the interface and also perform molecular dynamic simulation for ice-water interface regime.

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