Related papers: Phonon anharmonicity and soft-phonon mediated stru…
Structural phase transitions and soft phonon modes pose a longstanding challenge to computing electron-phonon (e-ph) interactions in strongly anharmonic crystals. Here we develop a first-principles approach to compute e-ph scattering and…
We investigate the electronic and magnetic properties as well as lattice dynamics and spin-phonon coupling of $\beta$-Na$_{0.33}$V$_2$O$_5$ using temperature-dependent Raman scattering, dc-magnetization and dc-resistivity, x-ray…
Inelastic neutron scattering is used to measure the temperature dependent phonon dispersion in Ca$_{2-x}$Sr$_{x}$RuO$_{4}$ ($x=0.4$, 0.6). The in-plane $\Sigma_{4}$ octahedral tilt mode softens significantly at the zone boundary of the high…
The doping dependence of the micro-Raman spectra of high quality La_{2-x}Sr_xCuO_4 microcrystals with x=0.0-0.45 has been investigated in the region 10-300 K. The phonon at ~100 cm^{-1} of the orthorhombic phase shows a classical soft mode…
The temperature dependence of the first-order phonon mode of single crystal of Silicon (Si) is determined by Raman scattering in a broad temperature range of 4-623 K. Our studies reveal the anomalous red-shift of the Raman active phonon…
Temperature-dependent Raman spectra of TbMnO$_3$ from 5 K to 300 K in the spectral range of 200 to 1525 cm$^{-1}$ show five first-order Raman allowed modes and two high frequency modes. The intensity ratio of the high frequency Raman band…
We have used a combination of ultrafast coherent phonon spectroscopy, ultrafast thermometry, and time-dependent Landau theory to study the inversion symmetry breaking phase transition at $T_c = 200$ K in the strongly spin-orbit coupled…
Synthetic powder, ore samples and mineral single crystals of goethite ($\alpha-$FeOOH) were investigated with polarized Raman spectroscopy at temperatures from 300 K to 473 K. The symmetry of the vibrational modes, observed in different…
We present here temperature-dependent Raman, x-ray diffraction and specific heat studies between room temperature and 12 K on single crystals of spin-ice pyrochlore compound $Dy_2Ti_2O_7$ and its non-magnetic analogue $Lu_2Ti_2O_7$. Raman…
We present a detailed temperature dependent Raman light scattering study of optical phonons in Ba{1-x}K{x}Fe{2}As{2} (x ~ 0.28, superconducting Tc ~ 29 K), Sr{1-x}K{x}Fe{2}As{2} (x ~ 0.15, Tc ~ 29 K) and non-superconducting BaFe{2}As{2}…
Using polarization-resolved Raman spectroscopy, we investigate layer number, temperature, and magnetic field dependence of Raman spectra in one- to four-layer $\mathrm{CrI_{3}}$. Layer-number-dependent Raman spectra show that in the…
In order to investigate the origin of the phase transition observed in NaV$_2$O$_5$, as well as its electronic structure, we have measured Raman intensities as a function of the laser wavelength above and below the phase transition…
Topological phase transitions occur when the electronic bands change their topological properties, typically featuring the closing of the bandgap. While the influence of topological phase transitions on electronic and optical properties has…
Temperature-dependent (5 K to 300 K) Raman scattering study of A$_{1g}$/A'$_1$ phonon modes in mono-layer (1L), bilayer (2L), trilayer (3L), and tetralayer (4L) MoTe$_2$ is reported. The temperature evolution of the modes' intensity…
Inelastic light scattering spectra of Bi_2Se_3 and Sb_2Te_3 single crystals have been measured over the temperature range from 5 K to 300 K. The temperature dependence of dominant A^{2}_{1g} phonons shows similar behavior in both materials.…
PbTe crystals have a soft transverse optical phonon mode in the terahertz frequency range, which is known to efficiently decay into heat-carrying acoustic phonons, resulting in anomalously low thermal conductivity. Here, we studied this…
We discuss the first infrared reflectivity measurement on a BiFeO3 single crystal between 5 K and room temperature. The 9 predicted ab-plane E phonon modes are fully and unambiguously determined. The frequencies of the 4 A1 c-axis phonons…
Diffusion is the underlying mechanism for many complicated materials phenomena, and understanding it is basic to the discovery of novel materials with desired physical and mechanical properties. Certain groups of solid phases, such as the…
The effects of phonon anharmonicity, phonon-magnon and electron-phonon interactions on the temperature dependence of Raman optical phonon modes are theoretically investigated. Besides of the Klemens result for the phonon width due to…
Materials having strong coupling between different degrees of freedom such as spin, lattice, orbital, and charge are of immense interest due to their potential device applications. Here, we have stabilized the 9R phase of BaMnO3, by Sr (Ti)…