Related papers: Raman Studies in MgB2-xCx
Room temperature Raman scattering measurements have been carried out on well characterized samples of MgB2-xCx. The Raman line corresponding to the E2g phonon mode shows progressive hardening from 620 cm-1 in pristine MgB2 to 775 cm-1 in…
We report Raman spectra and synchrotron x-ray diffraction measurements of lattice parameters of polycrystalline MgB2 under hydrostatic pressure conditions up to 15 GPa. An anomalously broadened Raman band at 620 cm-1 is observed that…
Phonon spectra have been investigated by micro-Raman scattering from 290 to 20K. New peaks at 500 and 674 cm-1 appear below 250K in MgB2. These peaks are explained by the Fermi resonance, where Raman-active E2g intereacts with the overtone…
The paper presents detailed Raman scattering study of the unusually broad E2g phonon mode in MgB2 crystal. For the first time, it is shown by the polarized Raman scattering on few-micron-size crystallites with natural faces that the…
Raman spectra of the MgB2 ceramic samples were measured as a function of pressure up to 32 GPa at room temperature. The spectrum at normal conditions contains a very broad peak at ~590 cm-1 related to the E2g phonon mode. The frequency of…
Raman scattering spectra from the ac-face of thick MgB2 single crystals were measured in zz, xz and xx polarisations. In zz and xz polarisations a threshold at around 29 cm^{-1} forms in the below Tc continuum but no pair-breaking peak is…
Electronic Raman scattering studies on MgB2 single crystals as a function of excitation and polarization have revealed three distinct superconducting features: a clean gap below 37 cm-1 and two coherence peaks at 109 cm-1 and 78 cm-1 which…
The paper presents polarized Raman scattering study on a few-micron-size crystallite of LiBC with natural faces. The experiment on as grown sample has revealed a four lattice modes with frequencies at 1276 cm^-1, 830 cm^-1, 546 cm^-1 and…
We report data on the Hall coefficient (RH) of the carbon substituted Mg(B1-xCx)2 single crystals with x in the range from 0 to 0.1. The temperature dependences of RH obtained for the substituted crystals differ systematically at low…
Polarized Raman scattering has been performed on CaC6 superconductor. We identify two of the three Raman active Eg phonon modes at 440 and 1508 cm-1 expected for the R-3m space group of CaC6. These first order scattering modes appear along…
Results of room temperature Raman scattering studies of ultrathin graphitic films supported on Si (111)/SiO2 substrates are reported. The results are significantly different from those known for graphite. Spectra were collected using 514 nm…
We study anharmonic effects in MgB2 by comparing Inelastic X-ray and Ramanscattering together with ab-initio calculations. Using high statistics and high q resolution measurements we show that the E2g mode linewidth is independent of…
Magneto Raman scattering study of the E$_{2g}$ optical phonons in multi-layer epitaxial graphene grown on a carbon face of SiC are presented. At 4.2K in magnetic field up to 33 T, we observe a series of well pronounced avoided crossings…
The effect of pressure on optical phonon frequencies of MgB$_2$ has been calculated using the frozen-phonon approach based on a pseudopotential method. Gr\"uneisen parameters of the harmonic mode frequencies are reported for the…
Polarisation-resolved Raman scattering measurements were performed on MgB_2 single crystals to determine the magnitude, symmetry and temperature dependence of the superconducting gap. A single sharp peak due to Cooper pair breaking appears…
Superconducting MgB$\_2$ shows an E$\_{2g}$ zone center phonon, as measured by Raman spectroscopy, that is very broad in energy and temperature dependent. The Raman shift and lifetime show large differences with the values elsewhere in the…
Raman scattering experiments on Na_{x}CoO_2 yH_2O single crystals show a broad electronic continuum with a pronounced peak around 100 cm-1 and a cutoff at approximately 560 cm-1over a wide range of doping levels. The electronic Raman…
We have studied, both experimentally and theoretically, the change of the so-called 2D band of the Raman scattering spectrum of graphene (the two-phonon peak near 2700 cm-1) in an external magnetic field applied perpendicular to the…
We report inelastic light scattering studies on Ca(Fe0.97Co0.03)2As2 in a wide spectral range of 120-5200 cm-1 from 5K to 300K, covering the tetragonal to orthorhombic structural transition as well as magnetic transition at Tsm ~ 160K. The…
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.…