Related Experiment Video
Updated: Jun 17, 2026
07:48
An Externally-Heated Diamond Anvil Cell for Synthesis and Single-Crystal Elasticity Determination of Ice-VII at High Pressure-Temperature Conditions
Published on: June 18, 2020
Hexagonal ice transforms at high pressures and compression rates directly into "doubly metastable" ice phases
Marion Bauer1, Katrin Winkel, Daniel M Toebbens
1Institute of General, Inorganic and Theoretical Chemistry, University of Innsbruck, Innrain 52a, A-6020 Innsbruck, Austria.
The Journal of Chemical Physics
|December 17, 2009
Summary
High compression rates during hexagonal ice experiments produce metastable ice phases like ice III and ice V, not just stable ice II. This finding offers a new method for discovering novel ice polymorphs.
Area of Science:
- Materials Science
- Geophysics
- Physical Chemistry
Background:
- Hexagonal ice (Ice Ih) is the most common form of ice under ambient conditions.
- Understanding ice phase transitions under pressure is crucial for various scientific fields, including planetary science and materials engineering.
Purpose of the Study:
- To investigate the influence of compression rate on the phase transitions of hexagonal ice at low temperatures (170-220 K) and high pressures (up to 1.6 GPa).
- To determine if varying compression rates can yield metastable ice polymorphs with potentially unique properties.
Main Methods:
- Compression and decompression experiments were conducted using a piston cylinder apparatus.
- Experiments were performed in the temperature range of 170-220 K and pressures up to 1.6 GPa.
- Compression rates were varied up to 4000 MPa/min.
Main Results:
- At low compression rates, hexagonal ice transforms into stable ice II, consistent with previous studies.
- At higher compression rates, increasing amounts of metastable ice III are formed from hexagonal ice.
- The critical compression rate for forming ice III decreases significantly with decreasing temperature.
- At the highest compression rates, a fraction of metastable ice V was also observed.
Conclusions:
- Increasing compression rates promote the formation of metastable ice polymorphs (ice III and ice V) from hexagonal ice.
- The mechanical and rheological properties of ice can be significantly altered by controlling the compression rate during phase transitions.
- Isothermal compression at low temperatures and high rates presents a promising method for exploring and synthesizing novel ice polymorphs for academic and industrial applications.
Related Concept Videos
02:39Phase Transitions: Melting and Freezing
Heating a crystalline solid increases the average energy of its atoms, molecules, or ions, and the solid gets hotter. At some point, the added energy becomes large enough to partially overcome the forces holding the molecules or ions of the solid in their fixed positions, and the solid begins the process of transitioning to the liquid state or melting. At this point, the temperature of the solid stops rising, despite the continual input of heat, and it remains constant until all of the solid is...
02:33Phase Transitions: Sublimation and Deposition
Some solids can transition directly into the gaseous state, bypassing the liquid state, via a process known as sublimation. At room temperature and standard pressure, a piece of dry ice (solid CO2) sublimes, appearing to gradually disappear without ever forming any liquid. Snow and ice sublimate at temperatures below the melting point of water, a slow process that may be accelerated by winds and the reduced atmospheric pressures at high altitudes. When solid iodine is warmed, the solid sublimes...
02:39Phase Diagrams
A phase diagram combines plots of pressure versus temperature for the liquid-gas, solid-liquid, and solid-gas phase-transition equilibria of a substance. These diagrams indicate the physical states that exist under specific conditions of pressure and temperature and also provide the pressure dependence of the phase-transition temperatures (melting points, sublimation points, boiling points). Regions or areas labeled solid, liquid, and gas represent single phases, while lines or curves represent...
01:19Phase Diagram
The phase of a given substance depends on the pressure and temperature. Thus, plots of pressure versus temperature showing the phase in each region provide considerable insights into the thermal properties of substances. Such plots are known as phase diagrams. For instance, in the phase diagram for water (Figure 1), the solid curve boundaries between the phases indicate phase transitions (i.e., temperatures and pressures at which the phases coexist).
01:24Phase Diagram
A phase diagram is a graphical representation of the physical states of a substance under different conditions of temperature and pressure. It shows the boundaries between solid, liquid, and gas phases and the conditions at which these phases coexist in equilibrium. An area in a phase diagram represents a single phase, whereas lines or phase boundaries represent the equilibrium between two phases.In the phase diagram of water, the boundary line between the solid and liquid states illustrates...
01:19Phase Changes
Phase transitions play an important theoretical and practical role in the study of heat flow. In melting or fusion, a solid turns into a liquid; the opposite process is freezing. In evaporation, a liquid turns into a gas; the opposite process is condensation.
A substance melts or freezes at a temperature called its melting point and boils or condenses at its boiling point. These temperatures depend on pressure. High pressure favors the denser form of the substance, so typically, high pressure...
A substance melts or freezes at a temperature called its melting point and boils or condenses at its boiling point. These temperatures depend on pressure. High pressure favors the denser form of the substance, so typically, high pressure...