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arXiv · 1301.5881

Investigation of infrared phonon modes in multiferroic single-crystal FeTe$_{2}$O$_{5}$Br

K. H. Miller·X. S. Xu·H. Berger·V. Craciun·X. Xi·C. Martin·G. L. Carr·D. B. Tanner
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Abstract

Reflection and transmission as a function of temperature (5--300 K) have been measured on single crystals of the multiferroic compound FeTe$_{2}$O$_{5}$Br utilizing light spanning the far infrared to the visible portions of the electromagnetic spectrum. The complex dielectric function and optical properties were obtained via Kramers-Kronig analysis and by fits to a Drude-Lortentz model. Analysis of the anisotropic excitation spectra via Drude-Lorentz fitting and lattice dynamical calculations have lead to the observation of all 52 IR-active modes predicted in the $ac$ plane and 43 or the 53 modes predicted along the b axis of the monoclinic cell. Assignments to groups (clusters) of phonons have been made and trends within them are discussed in light of our calculated displacement patterns.

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K. H. Miller, X. S. Xu, H. Berger, V. Craciun, X. Xi, C. Martin, G. L. Carr, D. B. Tanner. 2013-01-24. Investigation of infrared phonon modes in multiferroic single-crystal FeTe$_{2}$O$_{5}$Br. https://doi.org/10.1103/physrevb.87.224108

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