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High Pressure Single Crystal Diffraction at PX^2
Published on: January 16, 2017
B1-b2 transition in calcium oxide from shock-wave and diamond-cell experiments
Science (New York, N.Y.)
|November 16, 1979
Summary
Calcium oxide undergoes a structural transformation at high pressures, confirmed by shock-wave and diamond-cell experiments. This finding supports theories of Earth
Area of Science:
- Geophysics and high-pressure physics.
Background:
- Calcium oxide (CaO) is a key component in planetary interiors.
- Understanding its high-pressure behavior is crucial for models of Earth's mantle.
Purpose of the Study:
- To investigate the structural phase transition of calcium oxide under extreme pressures.
- To validate high-pressure measurement scales.
Main Methods:
- Utilizing shock-wave experiments to probe material properties at high pressures.
- Employing diamond-anvil cell techniques for static high-pressure measurements.
- Cross-validating pressure scales using ruby fluorescence.
Main Results:
- Observed a phase transition of calcium oxide from B1 to B2 structure between 60-70 GPa.
- Documented an 11% volume reduction during this transition.
- Confirmed the accuracy of the ruby fluorescence pressure scale up to 65 GPa.
Conclusions:
- The B1-B2 transition in CaO provides insights into lower mantle composition.
- Results support theories of inhomogeneous accretion in planetary formation.
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