Crystal structure and the Mott-Hubbard gap in YTiO(3) at high pressure
1Max-Planck-Institute for Solid State Research, Heisenbergstrasse 1, D-70569 Stuttgart, Germany.
Summary
High pressure alters YTiO(3) crystal structure, causing TiO(6) octahedra distortion around 10 GPa. This structural change is linked to reorienting Ti 3d orbitals and reduces the optical bandgap.
Area of Science:
- Solid-state physics
- Materials science
- Crystallography
Background:
- Yttrium titanate (YTiO3) exhibits complex electronic and structural properties.
- Understanding its behavior under pressure is crucial for potential applications.
Purpose of the Study:
- To investigate the crystal structure of YTiO3 at high pressures up to 30 GPa.
- To analyze the pressure-induced changes in TiO6 octahedra distortion and optical bandgap.
Main Methods:
- Synchrotron X-ray powder diffraction at 295 K.
- Mid-infrared synchrotron microspectroscopy.
Main Results:
- A distinct change in TiO6 octahedra distortion was observed around 10 GPa.
- Pressure-driven reorientation of Ti 3d(t2g) orbitals is proposed to explain structural changes.
- Quantitative reduction of the optical bandgap of YTiO3 was determined.
Conclusions:
- High pressure significantly influences the structural and electronic properties of YTiO3.
- Orbital reorientation plays a key role in the pressure-induced structural transitions.
- Observed changes in bandgap are consistent with structural and orbital modifications.
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