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.
Abstract:
The crystal structure of YTiO(3) at high pressures up to 30 GPa has been investigated by means of synchrotron x-ray powder diffraction (T = 295 K). The variation of the Ti-O bond lengths with pressure evidences a distinct change in the distortion of the TiO(6) octahedra at around 10 GPa, which is discussed in terms of a pressure-driven spatial reorientation of the occupied Ti 3d(t(2g)) orbitals. Mid-infrared synchrotron microspectroscopy has been used to determine quantitatively the pressure-induced reduction of the optical bandgap of YTiO(3), and the results are interpreted on the basis of the structural and possible orbital orientation changes.
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