Far-infrared spectra of the magnetic exchange resonances and optical phonons and their connection to magnetic and dielectric properties of Dy₃Fe₅O₁₂ garnet

Kang, T. D.; Standard, E. C.; Rogers, P. D.; Ahn, K. H.; Sirenko, Andrei A.; Dubroka, Adam; Bernhard, Christian; Park, S.; Choi, Y. J.; Cheong, S.-W.

doi:10.1103/PhysRevB.86.144112

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Journal article

Far-infrared spectra of the magnetic exchange resonances and optical phonons and their connection to magnetic and dielectric properties of Dy₃Fe₅O₁₂ garnet

Kang, T. D. Department of Physics, New Jersey Institute of Technology, Newark, USA
Standard, E. C. Department of Physics, New Jersey Institute of Technology, Newark, USA
Rogers, P. D. Department of Physics, New Jersey Institute of Technology, Newark, USA
Ahn, K. H. Department of Physics, New Jersey Institute of Technology, Newark, USA
Sirenko, Andrei A. Department of Physics, New Jersey Institute of Technology, Newark, USA
Dubroka, Adam Department of Physics, University of Fribourg, Switzerland
Bernhard, Christian Department of Physics, University of Fribourg, Switzerland
Park, S. Rutgers Center for Emergent Materials and Department of Physics and Astronomy, Rutgers University, Piscataway, New Jersey USA - Department of Physics, Chung-Ang University, Seoul, Korea
Choi, Y. J. Rutgers Center for Emergent Materials and Department of Physics and Astronomy, Rutgers University, Piscataway, New Jersey USA - Department of Physics and IPAP, Yonsei University, Seoul, Korea
Cheong, S.-W. Rutgers Center for Emergent Materials and Department of Physics and Astronomy, Rutgers University, Piscataway, New Jersey USA

19.10.2012

Published in:

Physical Review B - Condensed Matter and Materials Physics. - 2012, vol. 86, no. 14, p. 144112

English Far-infrared spectra of ferrimagnetic Dy₃Fe₅O₁₂ single crystals have been studied in the spectral range between 12 and 700 cm⁻¹ and in a wide temperature range between 5 K and 300 K using transmission spectroscopy and rotating analyzer ellipsometry. In the temperature range below T_C = 16 K for the magnetic ordering of Dy³⁺ spins, a number of ligand field and Kaplan-Kittel (KK) exchange resonance modes have been found. Temperature dependencies of their frequencies allowed us to estimate the ratio between the Fe-Dy and Dy-Dy exchange constants. We found that variation of the oscillator strength of the KK modes correlates with the magnetic-field-induced changes of magnetic permeability. The low-temperature peak in the static value of the dielectric function at T_C = 16 K may be related to the observed temperature-induced variation of the oscillator strength of the optical phonons.

Faculty

Faculté des sciences et de médecine

Department

Département de Physique

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