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arXiv · 1005.2705

Coupling between magnon and ligand-field excitations in magnetoelectric Tb3Fe5O12 garnet

T. D. Kang·E. Standard·K. H. Ahn·A. A. Sirenko·G. L. Carr·S. Park·Y. J. Choi·M. Ramazanoglu·V. Kiryukhin·S-W. Cheong
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Abstract

The spectra of far-infrared transmission in Tb3Fe5O12 magnetoelectric single crystals have been studied in the range between 15 and 100 cm-1, in magnetic fields up to 10 T, and for temperatures between 5 and 150 K. We attribute some of the observed infrared-active excitations to electric-dipole transitions between ligand-field split states of Tb3+ ions. Anticrossing between the magnetic exchange excitation and the ligand-field transition occurs at the temperature between 60 and 80 K. The corresponding coupling energy for this interaction is 6 cm-1. Temperature-induced softening of the hybrid IR excitation correlates with the increase of the static dielectric constant. We discuss the possibility for hybrid excitations of magnons and ligand-field states and their possible connection to the magnetoelectric effect in Tb3Fe5O12.

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T. D. Kang, E. Standard, K. H. Ahn, A. A. Sirenko, G. L. Carr, S. Park, Y. J. Choi, M. Ramazanoglu, V. Kiryukhin, S-W. Cheong. 2010-05-15. Coupling between magnon and ligand-field excitations in magnetoelectric Tb3Fe5O12 garnet. https://doi.org/10.1103/physrevb.82.014414

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