相关论文: Raman Studies in MgB2-xCx
Raman investigation of MoSe2 was carried out with eight different excitation energies. Seven peaks, including E1g, A1g, E2g1, and A2u2 peaks are observed in the range of 100-400 cm-1. The phonon modes are assigned by comparing the peak…
Single crystals of the optimally doped, moderately and strongly overdoped high temperature superconductor Tl2Ba2CuO6+x (Tl-2201) with Tc=80, 56 and 30K, respectively, have been investigated by polarized Raman scattering. By taking the peak…
We calculate the change in the superconducting transition temperature Tc of MgB2 caused by interband nonmagnetic impurity scattering using the Eliashberg theory for the two-band model of this compound. Much slower rate of Tc suppression is…
The paper presents a cooperative consideration of Raman spectra of $^2$ amorphous carbons as well as the nature and type of their amorphicity. The latter was attributed to the amorphization of a new type named as enforced fragmentation. The…
We report a high-pressure Raman spectroscopy study of a graphite-water mixture using water as the pressure-transmitting medium up to 9.9 GPa. In the graphite-rich region, three characteristic Raman features-the $E_{2g}^{(1)}$ shear mode,…
We present low temperature Raman measurements on Ca3Co2O6. Shell model lattice dynamics calculations were done to determine the vibrational pattern of the expected Raman modes. In the temperature window 300K to 52K the mode frequencies and…
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…
Raman excitation and emission spectra for the radial breathing mode (RBM) are reported, together with a preliminary analysis. From the position of the peaks on the two-dimensional plot of excitation resonance energy against Raman shift, the…
Raman and infrared absorption spectra of Mg(1-x)Al(x)B(2) have been collected for 0<x<0.5 in the spectral range of optical phonons. The x-dependence of the peak frequency, the width and the intensity of the observed Raman lines has been…
For many materials, Raman spectra are intricately structured and provide valuable information about compositional stoichiometry and crystal quality. Here we use density-functional theory calculations, mass approximation, and the Raman…
We report Raman scattering measurement of charge nematic fluctuations in the tetragonal phase of BaFe$_2$As$_2$ and Sr(Fe$_{1-x}$Co$_x$)$_2$As$_2$ (x=0.04) single crystals. In both systems, the observed nematic fluctuations are found to…
The system MgxB2 has been investigated to investigate possible nonstoichiometry in MgB2. When synthesized at 850oC, MgB2 is a line compound with a possible Mg vacancy content of about 1%. Small changes in lattice constants as a function of…
We report the detection of magnesium dicarbide, MgC$_2$, in the laboratory at centimeter wavelengths and assign $^{24}$MgC$_2$, $^{25}$MgC$_2$, and $^{26}$MgC$_2$ to 14 unidentified lines in the radio spectrum of the circumstellar envelope…
Polarized Raman spectra of the calcium vanadium oxide bronze beta-Ca0.33V2O5 are measured in the temperature range between 300 K and 20 K. The charge ordering phase transition at about 150 K is characterized by the appearance of the new…
The exceptional ability of carbon to form sp2 and sp3 bonding states leads to a great structural and chemical diversity of carbon-bearing phases at non-ambient conditions. Here we use laser-heated diamond anvil cells combined with…
Raman scattering data were collected on graphite monochromator. Spectra were interpreted in terms of the space group $P6_3mc$, a subgroup of space group $P6_3/mmc$. The latter has commonly been used for the interpretation of Raman…
The effect of surface degradation of the thermolectric cobaltite on Raman spectra is discussed and compared to experimental results from Co3O4 single crystals. We conclude that on NaCl flux grown NaxCoO2 crystals a surface layer of Co3O4…
Accurate and simple local strain assessment in graphene is one of the crucial tasks in device characterization. Raman spectroscopy is often used for that purpose through monitoring of the G and 2D modes. However, the shifts of those two…
High purity niobium (Nb), subjected to the processing methods used in the fabrication of superconducting RF cavities, displays micron-sized surface patches containing excess carbon. High-resolution transmission electron microscopy and…
Pressure-dependent Raman scattering studies in the range 0.0 -- 32 kbar were carried out in L-alanine in order to investigate its external mode phonon spectra in relation to the phase transitions in the crystal. A careful analysis of the…