Infrared phonon anomaly and magnetic excitations in single-crystal Cu$_{3}$Bi(SeO$_{3}$)$_{2}$O$_{2}$Cl

K. H. Miller; P. W. Stephens; C. Martin; E. Constable; R. A. Lewis; H. Berger; G. L. Carr; D. B. Tanner

doi:10.1103/PhysRevB.86.174104

paper

Infrared phonon anomaly and magnetic excitations in single-crystal Cu $_{3}$ Bi(SeO $_{3}$ ) $_{2}$ O $_{2}$ Cl

arXiv:1206.1610 · doi:10.1103/PhysRevB.86.174104

Abstract

Infrared reflection and transmission as a function of temperature have been measured on single crystals of Cu $_{3}$ Bi(SeO $_{3}$ ) $_{2}$ O $_{2}$ Cl. The complex dielectric function and optical properties along all three principal axes of the orthorhombic cell were obtained via Kramers-Kronig analysis and by fits to a Drude-Lorentz model. Below 115 K, 16 additional modes (8(E $∥ a^$ )+6(E $∥ b^$ )+2(E $∥ c^$ )) appear in the phonon spectra; however, powder x-ray diffraction measurements do not detect a new structure at 85 K. Potential explanations for the new phonon modes are discussed. Transmission in the far infrared as a function of temperature has revealed magnetic excitations originating below the magnetic ordering temperature ( $T_{c} \sim$ 24 K). The origin of the excitations in the magnetically ordered state will be discussed in terms of their response to different polarizations of incident light, behavior in externally-applied magnetic fields, and the anisotropic magnetic properties of Cu $_{3}$ Bi(SeO $_{3}$ ) $_{2}$ O $_{2}$ Cl as determined by d.c. susceptibility measurements.

12 pages, 12 figures

Infrared phonon anomaly and magnetic excitations in single-crystal Cu $_{3}$ Bi(SeO $_{3}$ ) $_{2}$ O $_{2}$ Cl

Abstract

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Infrared phonon anomaly and magnetic excitations in single-crystal Cu3​Bi(SeO3​)2​O2​Cl

Abstract

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Cited by in corpus (9)

Infrared phonon anomaly and magnetic excitations in single-crystal Cu $_{3}$ Bi(SeO $_{3}$ ) $_{2}$ O $_{2}$ Cl