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Structural Phase Transition and Disproportionation of MnF3 Under High Pressure and High Temperature
Jie Liu1, Jinming Zhu1, Hongyu Yu1
1State Key Laboratory of Superhard Materials, College of Physics, Jilin University, Changchun 130012, China.
Inorganic Chemistry
|August 15, 2024
Summary
High pressure and temperature transform manganese trifluoride (MnF3) into a new phase and then cause it to self-disproportionate into MnF2 and MnF4. This study reveals novel behavior in transition metal fluorides under extreme conditions.
Area of Science:
- Materials Science
- Solid-State Chemistry
- High-Pressure Physics
Background:
- Manganese trifluoride (MnF3) exhibits a distorted octahedral crystal structure due to the Jahn-Teller effect.
- Extreme conditions of high pressure and temperature can induce unusual phenomena in materials, challenging existing theories.
Purpose of the Study:
- To investigate the structural phase transition of MnF3 under high pressure.
- To explore the self-disproportionation behavior of MnF3 at high pressure and temperature.
Main Methods:
- Synchrotron radiation X-ray diffraction (XRD) was used to confirm structural changes.
- Raman spectroscopy and UV-vis absorption experiments were employed to analyze material properties.
- Laser heating was utilized to achieve high-temperature conditions.
Main Results:
- MnF3 undergoes a structural phase transition from the I2/a phase to the Pnma phase under high pressure.
- Molten Pnma-MnF3 self-disproportionates into MnF2 and MnF4 at pressures above 57.1 GPa.
- Equations of state for Mn-F compounds under pressure were determined.
Conclusions:
- This research elucidates the high-pressure, high-temperature phase behavior of MnF3.
- The findings provide insights into the stability and transformations of transition metal fluorides under extreme conditions.
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