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Updated: Dec 11, 2025
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Chemical Synthesis of Porous Barium Titanate Thin Film and Thermal Stabilization of Ferroelectric Phase by Porosity-Induced Strain
Published on: March 27, 2018
11.4K
Phase transitions in Bi4Ti3O12
Vladimir B Shirokov1, Mikhail V Talanov2
1South Scientific Center, Russian Academy of Sciences, Rostov-on-Don, Russian Federation.
Summary
This study investigates structural distortions in bismuth titanate (Bi4Ti3O12) using group-theoretical methods. A thermodynamic model explains phase transitions, revealing direct or intermediate pathways to the ferroelectric phase.
Area of Science:
- Solid State Physics
- Materials Science
- Crystallography
Background:
- Bismuth titanate (Bi4Ti3O12) belongs to the Aurivillius family of layered perovskites.
- These materials exhibit high-temperature ferroelectricity, making them promising for applications like random-access memory.
- Their structural complexity arises from intricate interactions of degrees of freedom.
Purpose of the Study:
- To investigate structural distortions in the high-symmetry phase of Bi4Ti3O12.
- To develop a Landau theory-based thermodynamic model for phase transitions.
- To elucidate the mechanisms and pathways of phase transitions in Bi4Ti3O12.
Main Methods:
- Group-theoretical analysis of structural distortions.
- Modeling of structural distortions via rotations and displacements of octahedra.
- Landau theory for constructing a thermodynamic model of phase transitions.
Main Results:
- Identified connections between octahedra rotations and displacements.
- Constructed a stable thermodynamic model with three order parameters.
- Phenomenological phase diagram predicts direct or intermediate transitions to the ferroelectric phase.
Conclusions:
- The phase transition from the tetragonal to the ferroelectric phase can occur directly or via intermediate states.
- Discussed the role of improper order parameters in phase transitions.
- Explored possible domain configurations in the low-temperature ferroelectric phase structure.
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