相关论文: Raman evidence for Orbiton-Mediated Multiphonon Sc…

We report multiphonon Raman scattering in graphene samples. Higher order combination modes involving 3 phonons and 4 phonons are observed in single-layer (SLG), bi-layer (BLG), and few layer (FLG) graphene samples prepared by mechanical…

We calculated the infrared conductivity spectrum of orbitally ordered LaMnO$_3$ in phonon frequency and overtone frequency ranges. We considered orbital exchange, Jahn-Teller electron-phonon coupling, and phonon--phonon coupling. The…

Raman spectra from silicon nanostructures, recorded using excitation laser power density of 1.0 kW/cm^2, is employed here to reveal the dominance of thermal effects at temperatures higher than the room temperature. Room temperature Raman…

The polarized Raman scattering spectra from freshly cleaved $ab$, $ac$, and $bc$ surfaces of high quality twin free YBa$_2$Cu$_3$O$_{6.5}$ (Ortho-II) single crystals ($T_c$=57.5 K and $\Delta T = 0.6$ K) were studied between 80 and 300 K.…

We have performed polarized Raman scattering measurements on the newly discovered superconductor Ba$_{2}$Ti$_{2}$Fe$_{2}$As$_{4}$O$_{2}$ ($T_c = 21$ K). We observe seven out of eight Raman active modes, with frequencies in good accordance…

We examine anharmonic contributions to the optical phonon modes in bulk $T_d$-MoTe$_2$ through temperature-dependent Raman spectroscopy. At temperatures ranging from 100 K to 200 K, we find that all modes redshift linearly with temperature…

Raman scattering experiments have been carried out on single crystals of Nd$_{0.5}$Sr$_{0.5}$MnO$_3$ as a function of temperature in the range of 320-50 K, covering the paramagnetic insulator-ferromagnetc metal transition at 250 K and the…

The infrared (IR) reflectivity spectra of orthorhombic manganese perovskites PrMnO$_3$ and CaMnO$_3$ are studied in the frequency range of optical phonon modes at temperatures varying from 300 to 4 K. The IR phonon spectra of these two…

We present a comparative far-infrared reflection spectroscopy study of phonons, phase transitions, spin-phonon and electron-phonon interactions in isostructural multiferroic iron borates of gadolinium and terbium. The behavior of phonon…

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 report inelastic neutron scattering measurements of the phonon spectra in a pure powder sample of the multiferroic material BiFeO3. A high-temperature range was covered to unravel the changes in the phonon dynamics across the Neel (T_N ~…

We report temperature-dependent Raman scattering and X-ray diffraction studies of pyrochlore iridates, (Eu$_{1-x}$Bi$_x$)$_2$Ir$_2$O$_7$, for x=0, 0.02, 0.035, 0.05 and 0.1. The temperature variation in Raman experiments spans from 4 K to…

Raman scattering is used to observe pronounced electronic excitations around 230 meV - well above the two-phonon range - in the Mott insulators LaTiO$_3$ and YTiO$_3$. Based on the temperature, polarization, and photon energy dependence,…

We report a systematic investigation of orthorhombic perovskite-type RCrO3 powder samples by Raman scattering for nine different rare earth R3+ cations (R = Y, La, Pr, Sm, Gd, Dy, Ho, Yb, Lu). The room-temperature Raman spectra and the…

We present a comprehensive study of polar and magnetic excitations in BiFeO3 ceramics and a thin film epitaxially grown on an orthorhombic (110) TbScO3 substrate. Infrared reflectivity spectroscopy was performed at temperatures from 5 to…

The Raman spectra of CaFe2O4 were measured with several exact scattering configurations between 20 and 520K and the symmetry of all observed Raman lines was determined. The Ag and B2g lines were assigned to definite phonon modes by…

Raman scattering on phonon--plasmon coupled modes in high magnetic fields is considered theoretically. The calculations of the dielectric function were performed in the long-wave approximation for the semiclassical and ultra-quantum…

Materials which possess coupling between different degrees of freedom such as charge, spin, orbital and lattice are of tremendous interest due to their potential for device applications. It has been recently realized that some of manganite…

High-pressure phase of boron oxide, orthorhombic \b{eta}-B2O3, has been studied in situ by synchrotron X-ray diffraction to 22 GPa and Raman scattering to 46 GPa at room temperature. The bulk modulus of \b{eta}-B2O3 has been found to be…

The discovery of 2-dimensional (2D) materials, such as CrI3, that retain magnetic ordering at monolayer thickness has resulted in a surge of research in 2D magnetism from both pure and applied perspectives. Here, we report a magneto-Raman…