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. 2012-10-19 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. application/pdf https://folia.unifr.ch/global/documents/302704 https://folia.unifr.ch/documents/302704/files/ber_fis.pdf eng info:eu-repo/semantics/altIdentifier/doi/10.1103/PhysRevB.86.144112 info:eu-repo/semantics/openAccess License undefined Physical Review B - Condensed Matter and Materials Physics. - 2012, vol. 86, no. 14, p. 144112 info:eu-repo/classification/udc/53 Far-infrared spectra of the magnetic exchange resonances and optical phonons and their connection to magnetic and dielectric properties of Dy₃Fe₅O₁₂ garnet http://purl.org/coar/resource_type/c_6501