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Pressure-induced phase transition in α- and β-BiNbO4.
Xingbang Dong1,2, Zhanbiao Huangfu1,2, Shiquan Feng1,2
1School of Physics and Electronic Engineering, Zhengzhou University of Light Industry, Zhengzhou, Henan, 450002, China. wz7907@163.com.
Physical Chemistry Chemical Physics : PCCP
|August 23, 2022
Summary
Bismuth niobate (BiNbO4) exhibits reversible phase transitions under high pressure. Researchers identified new crystal structures for orthorhombic and triclinic BiNbO4, offering insights into pressure-induced changes in polymorphic compounds.
Area of Science:
- Materials Science
- Solid State Chemistry
- Crystallography
Background:
- Bismuth niobate (BiNbO4) is recognized for its significant photocatalytic properties.
- The material exhibits rich polymorphism, with distinct structural phases.
- Understanding structural behavior under extreme conditions is crucial for materials development.
Purpose of the Study:
- To investigate the structural stability and evolution of orthorhombic (α-) and triclinic (β-) BiNbO4 under high pressure.
- To identify the crystal structures of high-pressure phases in BiNbO4.
- To explore the reversibility of pressure-induced phase transitions in BiNbO4.
Main Methods:
- In situ X-ray diffraction (XRD) patterns were employed to monitor structural changes.
- Raman spectroscopy was utilized to complement XRD analysis under compression.
- Experiments were conducted up to a maximum pressure of 46.7 GPa.
Main Results:
- Both α- and β-BiNbO4 samples showed instability upon compression.
- α-BiNbO4 transformed to a monoclinic C2/c structure at 10.3 GPa.
- β-BiNbO4 underwent an isostructural phase transition (P1̄ to P1) around 12.7 GPa, with identified crystal structures.
- High-pressure phases remained stable up to 46.7 GPa without symmetry changes.
- Both phase transitions were reversible upon pressure release.
Conclusions:
- High pressure induces reversible phase transitions in both α- and β-BiNbO4.
- New high-pressure crystal structures for BiNbO4 were identified.
- The findings offer valuable insights into pressure-induced phase transitions in polymorphic ABO4 compounds.
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