Modifying the magnetoelectric coupling in TbMnO.sub.3./sub. by low-level Fe.sup.3+./sup. substitution

0570777 - FZÚ 2024 RIV US eng J - Článek v odborném periodiku
Alves Maia, André Filipe - Vilarinho, R. - Kadlec, Christelle - Lebeda, Miroslav - Mihálik, M. Jr. - Zentková, M. - Mihálik, M. - Moreira, J.A. - Kamba, Stanislav
Modifying the magnetoelectric coupling in TbMnO₃ by low-level Fe³⁺ substitution.
Physical Review B. Roč. 107, č. 10 (2023), č. článku 104410. ISSN 2469-9950. E-ISSN 2469-9969
Grant CEP: GA ČR(CZ) GA21-06802S; GA MŠMT(CZ) EF16_019/0000760
Grant ostatní: OP VVV - SOLID21(XE) CZ.02.1.01/0.0/0.0/16_019/0000760
Institucionální podpora: RVO:68378271
Klíčová slova: ferroelectricity * lattice dynamics * magnetic phase transitions * spin-phonon coupling
Obor OECD: Condensed matter physics (including formerly solid state physics, supercond.)
Impakt faktor: 3.7, rok: 2022
Způsob publikování: Omezený přístup
https://doi.org/10.1103/PhysRevB.107.104410

We report a comprehensive study of the low-level substitution of Mn3+ by Fe3+ effect on the static and dynamic magnetoelectric coupling in TbMn1−xFexO3 (x=0, 0.02, and 0.04). Low-lying electromagnon excitation is activated in the cycloidal modulated antiferromagnetic and ferroelectric phase in TbMnO3, while it is observed up to TN in the Fe-substituted compounds, pointing at different mechanisms for static and dynamic magnetoelectric coupling. A second electrically active excitation near 40 cm−1 is explained by means of Tb3+ crystal-field effects. This excitation is observed up to room temperature, and exhibits a remarkable 15 cm−1 downshift on cooling in Fe-substituted compounds. Both electromagnon and crystal-field excitations are found to be coupled to the polar phonons with frequencies up to 250 cm−1. The anomalies in the T dependence of magnetic susceptibility above TN are well accounted for by spin-phonon coupling and crystal-field excitation, coupled to oxygen motions.
Trvalý link: https://hdl.handle.net/11104/0342119