A New Type of Ice

June 09, 2014

The research group in Okayama University Graduate School of Natural Science and Technology has discovered that a new ice form appears during the transition from liquid water to ice VII under high temperature and high pressure by using computerized molecular simulations.

The findings were published online June 6, 2014 in the journal Physical Chemistry Chemical Physics.
http://pubs.rsc.org/en/content/articlelanding/2014/cp/c4cp01616e#!divAbstract

Ice changes its crystal structure according to the surrounding temperature and pressure. Sixteen kinds of ice crystal structure are known. Ice VII exists in high pressure conditions and doesn’t melt even at temperatures over 100℃; Ice VII is known as a kind of “hot ice” for this reason. The existence of Ice VII is predicted on giant planets such as Neptune.
However, the formation pathway of ice VII was not clear.
In this study, the entire crystallization process of Ice VII from liquid water was observed in intervals of one picosecond and the formation mechanism of ice VII was revealed on the molecular level. A new ice form was discovered during this process. The ice form is a new kind of “hot ice” and has a totally new crystal formation.

The findings are expected to lead to the understanding of water characteristics as well as the geology and the climate on giant planets. In addition, the findings could lead to a new aspect of phase-transition mechanisms.


Contact Information:
Mototaka Senda, Ph.D.
US Representative
Intellectual Property Office, Organization for Research Promotion and Collaboration, Okayama University
Fremont, California USA
TEL: 1-510-797-0907
Email: takasenda@okayama-u.ac.jp

Masakazu Matsumoto, Ph.D.
Graduate School of Natural Science and Technology, Okayama University, Okayama Japan