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arXiv · 1910.05009

Optical spectroscopy on the photo-response in multiferroic BiFeO$_3$ at high pressure

F. Meggle·J. Ebad-Allah·J. Kreisel·C. A. Kuntscher
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Abstract

The pressure dependence of light-induced effects in single-crystalline BiFeO$_3$ is studied by optical spectroscopy. At low pressures, we observe three light-induced absorption features with energies just below the two crystal field excitations and the absorption onset, respectively. These absorption features were previously ascribed to excitons, possibly connected with the ultra-fast photostriction effect in BiFeO$_3$. The pressure-induced redshift of the absorption features follows the pressure dependence of the corresponding crystal field excitations and absorption onset, suggesting the link between them. Above the structural phase transition at $P_{\mathrm{c1}}\approx{}3.5$ GPa the three absorption features disappear, suggesting their connection to the polar phase in BiFeO$_3$. The pressure-induced disappearance of the photo-induced features is irreversible upon pressure release.

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F. Meggle, J. Ebad-Allah, J. Kreisel, C. A. Kuntscher. 2019-10-11. Optical spectroscopy on the photo-response in multiferroic BiFeO$_3$ at high pressure. https://doi.org/10.1063/1.5125741

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