相关论文: Raman Studies in MgB2-xCx

We present results of Raman scattering experiments in differently doped Bi-2212 single crystals. Below Tc the spectra show pair-breaking features in the whole doping range. The low frequency power laws confirm the existence of a…

We report Raman scattering experiments on the strongly correlated electron system NaxCoO2 with x= 0.71 and ordered Na vacancies. In this doping regime, NaxCoO2 exhibits a large and unusual thermopower and becomes superconducting upon…

We have performed Raman-scattering measurements on high-quality single crystals of A$_{0.8}$Fe$_{1.6}$Se$_2$ superconductors of several compositions. We find a broad, asymmetric peak around 1600 cm$^{-1}$ (200 meV), which we identify as a…

2H-TaSe2 is a model transition metal dichalcogenide material that develops charge density waves (CDWs).Here we present variable-temperature Raman spectroscopy study on both incommensurate charge density waves (ICDW) and optical phonon modes…

We compute Raman scattering intensities via the lowest-order coupling to the bosonic propagator associated with orbital nematic fluctuations in a minimal model for iron pnictides. The model consists of two bands on a square lattice…

Raman spectra of few-layer WS2 have been measured with up to seven excitation energies, and peculiar resonance effects are observed. The two-phonon acoustic phonon scattering signal close to the main E2g1 peak is stronger than the main…

The electrical conductivity anisotropy of the sigma-bands is calculated for the (Mg,Sc)B2 system using a virtual crystal model. Our results reveal that anisotropy drops with relatively little scandium content (< 30%); this behaviour…

Tunneling data on MgB_{1.8}C_{0.2} show a reduction in the energy gap of the pi-bands by a factor of two from undoped MgB2 that is consistent with the Tc reduction, but inconsistent with the expectations of the dirty limit. Dirty-limit…

The luminescence and Raman spectra of the Cs2ZrCl6 crystal in a wide range of pressures were studied in this work for the first time. Luminescence measurements were performed up to 10 GPa, while the Raman spectra were measured up to 20 GPa.…

We have studied the changes in the electronic structure and the superconducting transition temperature T_c of Mg(B_{1-x}C_{x})_{2} alloys as a function of x with 0\leq x\leq 0.3. Our density-functional-based approach uses coherent-potential…

Electron diffraction and high resolution microscopy have been performed on Mg1-xAlxB2 with x~0.5. This composition displays a superstructure with a repeat period of exactly 2c along the c axis and about 10 nm in the a-b plane. The…

Second-order Raman scattering has been extensively studied in carbon-based nanomaterials, \emph{e.g.} nanotube and graphene, because it activates normally forbidden Raman modes that are sensitive to crystal disorder, such as defects,…

We have measured polarized Raman scattering spectra of the Fe$_{1-x}$Co$_{x}$Sb$_{2}$ and Fe$_{1-x}$Cr$_{x}$Sb$_{2}$ (0$\leq x\leq $0.5) single crystals in the temperature range between 15 K and 300 K. The highest energy $B_{1g}$ symmetry…

The broad Mg II line in quasars has distinct variability properties compared with broad Balmer lines: it is less variable, and usually does not display a "breathing" mode, the increase in the average cloud distance when luminosity…

A c-axis oriented thin film and a high density sintered pellet of MgB2 have been studied by x-ray photoemission spectroscopy, and compared to measurements from MgO and MgF2 single crystals. The as-grown surface has a layer which is Mg-rich…

Resonant Raman spectra of single layer WS$_{2}$ flakes are presented. A second order Raman peak (2LA) appears under resonant excitation with a separation from the E$^{1}_{2g}$ mode of only $4$cm$^{-1}$. Depending on the intensity ratio and…

We present extensive Scanning Tunneling Spectroscopy (STM/S) measurements at low temperatures in the multiband superconductor MgB$_2$. We find a similar behavior in single crystalline samples and in single grains, which clearly shows the…

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…

This paper presents an evaluation of two commonly accepted Raman linewidth models typically used to fit CARS model parameters to data; the Modified Exponential Gap (MEG) and the Energy Corrected Sudden (ECS) models. The adjustable…

The influence of lattice strain and Mg vacancies on the superconducting properties of MgB2 samples has been investigated. High quality samples with sharp superconducting transitions were synthesized. The variation in lattice strain and Mg…