Faculté des sciences

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, A. A. ; Dubroka, Adam ; Bernhard, Christian ; Park, S. ; Choi, Y. J. ; Cheong, S.-W.

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

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 TC = 16 K for the magnetic ordering of Dy³⁺ spins, a number of ligand field and... Plus

Ajouter à la liste personnelle
    Summary
    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 TC = 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 TC = 16 K may be related to the observed temperature-induced variation of the oscillator strength of the optical phonons.