Related papers: Optical phonons and magneto-elastic coupling in th…
The optical properties of the superconducting single crystal Rb$_{0.8}$Fe$_{1.68}$Se$_2$ with $T_{c}$ $\simeq$ 31 K have been measured over a wide frequency range in the $ab$ plane. We found that the optical conductivity is dominated by a…
The infrared reflectance of the transition metal chalcogenide 1T-TaS2 has been measured at temperatures from 30K to 360K over 30-45,000cm^-1 (4meV-5.5eV). The optical conductivity was obtained by Kramers-Kronig analysis. At 360K only modest…
The optical properties of magnetite at room temperature were studied by infrared reflectivity measurements as a function of pressure up to 8 GPa. The optical conductivity spectrum consists of a Drude term, two sharp phonon modes, a…
Critical behavior of the infrared reflectivity of RuSr_2GdCu_2O_8 ceramics is observed near the superconducting T_{SC} = 45 K and magnetic T_M = 133 K transition temperatures. The optical conductivity reveals the typical features of the…
We studied the optical properties of antiferromagnetic ZnCr2Se4 by infrared spectroscopy up to 28,000 cm-1 and for temperatures from 5 to 295 K. At the magnetic phase transition at 21 K, one of the four phonon modes reveals a clear…
Reflection and transmission as a function of temperature have been measured on a single crystal of the magnetoelectric ferrimagnetic compound Cu$_{2}$OSeO$_{3}$ utilizing light spanning the far infrared to the visible portions of the…
Near normal incident far-infrared reflectivity spectra of [111] dysprosium titanate (Dy2Ti2O4) single crystal have been measured at different temperatures. Seven phonon modes (eight at low temperature) are identified at frequency below 1000…
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…
We have measured near normal incidence far infrared (FIR) reflectivity spectra of a single crystal of TbMnO3 from 10K to 300K in the spectral range of 50 cm$^{-1}$ to 700 cm$^{-1}$. Fifteen transverse optic (TO) and longitudinal optic (LO)…
We report infrared reflectivity spectra for a new correlated cupric oxide system Sr2Cu(Re0.69Ca0.31)Oy with y ~ 0.6 at several temperatures ranging between 8 and 380 K. The reflectivity spectrum at 300 K comprises of several optical…
From an investigation of the optical conductivity of FeSi single crystals using FTIR spectroscopy in the frequency range from 30 to 20000 wavenumbers we conclude that the transverse effective charge of the Fe and Si ions is approximately…
A series of infrared-active optical phonons have been detected in type-I clathrate Ba$_8$Ga$_{16}$Ge$_{30}$ by terahertz time-domain spectroscopy. The conductivity spectra with the lowest-lying peaks at 1.15 and 1.80 THz are identified with…
Phonon measurements in the A15-type superconductors were complicated in the past because of the unavailability of large single crystals for inelastic neutron scattering, e.g., in the case of Nb$_3$Sn, or unfavorable neutron scattering…
We measured the reflectivity of a single crystal of FeSi from the far-infrared to the visible region (50-20000 wavenumber), varying the temperature between 4 and 300 K. The optical conductivity function was obtained via Kramers-Kronig…
We report on the structural and spectroscopic characterization of the multiferroic Fe$_2$Mo$_3$O$_8$. Synchrotron x-ray and neutron diffraction, as well as thermal expansion measurements reveal a lattice anomaly at $T_{\mathrm{N}}\simeq…
Reflection and transmission as a function of temperature (5--300 K) have been measured on single crystals of the multiferroic compound FeTe$_{2}$O$_{5}$Br utilizing light spanning the far infrared to the visible portions of the…
We report temperature evolution of coherently excited acoustic and optical phonon dynamics in superconducting iron pnictide single crystal Ca(Fe_0.944Co_0.056)_2As_2 across the spin density wave transition at T_SDW ~ 85 K and…
The temperature and pressure dependence of the partial density of phonon states of iron atoms in superconducting Fe1.01Se was studied by 57Fe nuclear inelastic scattering (NIS). The high energy resolution allows for a detailed observation…
The effect of the presence of electron-phonon (e-ph) coupling in the SiC, GeC and SnC hybrids is studied in the framework of the ab initio perturbation theory. The electronic bang gap thermal dependence reveals a normal monotonic decrease…
The evolution of the optical phonons in layered semiconductor alloys SnSe1-xSx is studied as a function of the composition by using polarized Raman spectroscopy with six different excitation wavelengths (784.8, 632.8, 532, 514.5, 488, and…