1999 Fiscal Year Final Research Report Summary
Equilibrium shape of ice Ih and roughening transition of prism facet
| Project/Area Number |
09640405
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
固体物性Ⅰ(光物性・半導体・誘電体)
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| Research Institution | Osaka City University |
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Principal Investigator |
MARUYAMA Minoru Department of Physics, Osaka City University, Lecturer, 理学部, 講師 (60117976)
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| Co-Investigator(Kenkyū-buntansha) |
SAWADA Tsutomu National Institute for Research in Inorganic Materials, Senior Researcher, 無機材質研究所, 主任研究官
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| Project Period (FY) |
1997 – 1998
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| Keywords | ice crystal / roughening / melting curve / equilibrium shape / high pressure |
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| Research Abstract |
We have investigated equilibrium shape of ice Ih along the melting curve under high pressures. The equilibrium shape showed phase transition from a circular disk to a hexagonal plate at -15℃ and 1600 bar. This represents that roughening transition occurred on prism facets at the point. However, growth and melting shapes exhibited hexagonal anisotropy near the roughening point, whereas equilibrium shape was circular and isotropic. In addition, their hexagonal orientations were rotated by 30°. Three shapes were different near the roughening point.
We also have measured the melting curve on which ice neither grows nor melts in water ; as a result, there was a discontinuity on the melting curve at -15℃ and 1600 bar. The roughening and discontinuity points agree well. This is puzzling, because roughening transition is the second-order phase transition and affects nothing on the melting curve. If the discontinuity has no relation with roughening, it can be attributable to some phase transition in ice or water, not in an ice/water interface for roughening.
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