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Orientational Transition in a Liquid Crystal Triggered by the Thermodynamic Growth of Interfacial Wetting Sheets
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Pressure-Induced Structural Phase Transition in Ho2Ce2O7 Oxide
1State Key Laboratory of High Pressure and Superhard Materials, Jilin University, Changchun 130012, China.
Materials (Basel, Switzerland)
|June 27, 2025
Summary
High pressure transforms Ho2Ce2O7
Area of Science:
- Materials Science
- Solid-State Chemistry
- High-Pressure Physics
Background:
- Ho2Ce2O7 exhibits a C-type cubic rare earth oxide structure at ambient conditions.
- Understanding structural stability under pressure is crucial for materials applications.
Purpose of the Study:
- To investigate the structural evolution of Ho2Ce2O7 under high pressure.
- To identify pressure-induced phase transitions and their characteristics.
Main Methods:
- Synchrotron X-ray diffraction up to 31.5 GPa.
- Raman spectroscopy up to 41.7 GPa.
Main Results:
- A pressure-induced phase transition initiated at 23.8 GPa.
- The transition involves cation disordering and coordination changes.
- A metastable hexagonal phase (R-3c) coexists with the parent cubic phase (Ia-3) above the transition pressure.
Conclusions:
- The structural transition in Ho2Ce2O7 is irreversible.
- The high-pressure phase is retained upon decompression to ambient conditions.
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