Quantifying the change in optical absorption caused by the ferro- to paraelectric transition in Sm-substituted BiFeO3 powders
Auteurs
Hill C., Melchiorre M., Milesi-Brault C., Gemeiner P., Karolak F., Bogicevic C., Dkhil B., Cañero-Infante I., Guennou M.
Référence
Journal of Applied Physics, vol. 138, n° 6, art. no. 064103, 2025
Description
The substitution of bismuth by samarium in BiFeO 3 is known to induce a structural phase transition from the polar phase to a non-polar phase, with a possible antiferroelectric intermediate structure. In this paper, we investigate the impact of this phase change on the optical properties. The optical bandgap was measured by diffuse reflectance as a function of temperature for several samarium concentrations across the structural phase transition. We found that the optical bandgap for each of the pure phases varies linearly with temperature and that the phase transitions are revealed by smooth transitions between those linear regimes. This allows us to quantify the contribution of the structural change in the optical absorption. We find that a difference in optical bandgap of about ≈ 130 meV can be attributed to the phase change. We anticipate that the same change could be obtained by applying an electric field in an antiferroelectric composition.
