Electrical conductivity of ice VII
Taku Okada1, Toshiaki Iitaka2, Takehiko Yagi3
1Institute for Solid State Physics, University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8581, Japan.
Scientific Reports
|July 23, 2014
Summary
Electrical conductivity of ice VII shows a peak near 10 GPa due to a charge carrier transition. This finding impacts understanding of ice properties under high pressure.
Area of Science:
- Geophysics and condensed matter physics.
Background:
- High-pressure behavior of ice is crucial for planetary science.
- Understanding electrical conductivity in ice under extreme conditions is challenging.
Purpose of the Study:
- To investigate the electrical conductivity of ice VII under high pressure.
- To identify the underlying mechanisms responsible for observed conductivity changes.
Main Methods:
- Electrical conductivity measurements using impedance spectroscopy.
- High-pressure experiments conducted in a diamond anvil cell (DAC).
- Temperature-dependent conductivity analysis (278 K to 303 K).
- Theoretical modeling and molecular dynamics simulations.
Main Results:
- A distinct peak in electrical conductivity of ice VII was observed around 10 GPa.
- Activation energy for conductivity reached a minimum near this pressure (Pc).
- Simulations indicated a transition from rotational to ionic defects as the primary charge carriers.
Conclusions:
- The observed conductivity peak is attributed to a fundamental change in charge transport mechanisms in ice VII.
- This transition from rotational to ionic defects influences the material's electrical properties under pressure.
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