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Synthesis and Microdiffraction at Extreme Pressures and Temperatures
Published on: October 7, 2013
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Structural Phase Transition of ThC Under High Pressure.
1Shanghai Institute of Applied Physics, Chinese Academy of Sciences (CAS), Shanghai, 201800, China.
Scientific Reports
|March 10, 2017
Summary
Thorium monocarbide (ThC) undergoes a pressure-induced phase transition from B1 to P4/nmm at ~58 GPa. This study reveals a significant volume collapse and provides a new elastic modulus for ThC.
Area of Science:
- Materials Science
- Condensed Matter Physics
- Nuclear Engineering
Background:
- Thorium monocarbide (ThC) is a candidate fuel for advanced nuclear reactors.
- Previous studies have not reported pressure-induced structural phase transitions in ThC.
- Understanding ThC's behavior under pressure is crucial for its application in nuclear energy.
Purpose of the Study:
- To experimentally investigate the structural stability of Thorium monocarbide (ThC) under high pressure.
- To identify any pressure-induced phase transitions in ThC.
- To determine the elastic properties of ThC at ambient conditions.
Main Methods:
- Synchrotron X-ray diffraction was employed to probe the crystal structure of ThC.
- High-pressure experiments were conducted at ambient temperature.
- Analysis of diffraction patterns identified structural changes and phase transitions.
Main Results:
- The study experimentally observed a phase transition of ThC from the B1 phase to the P4/nmm phase at approximately 58 GPa.
- A significant volume collapse of 10.2% was measured during this phase transition.
- The bulk modulus of ThC at ambient pressure was determined to be 147 GPa.
Conclusions:
- Thorium monocarbide (ThC) exhibits a pressure-induced structural phase transition at high pressures.
- The observed phase transition and volume collapse have implications for ThC's use as nuclear fuel.
- The determined elastic modulus refines previous estimations and highlights the importance of stoichiometry.
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