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Related papers: Raman Studies in MgB2-xCx

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The electronic properties of the carbon substituted MgB$_2$ single crystals are reported. The carbon substitution drops T$_c$ below 2 K. In-plane resistivity shows a remarkable increase in residual resistivity by C-substitution, while the…

Superconductivity · Physics 2009-11-10 T. Masui , S. Lee , S. Tajima

We experimentally quantify the Raman scattering from individual carbyne chains confined in double-walled carbon nanotubes. We find that the resonant differential Raman cross section of confined carbyne is on the order of $10^{-22}$…

Mesoscale and Nanoscale Physics · Physics 2020-08-18 Cla Duri Tschannen , Georgy Gordeev , Stephanie Reich , Lei Shi , Thomas Pichler , Martin Frimmer , Lukas Novotny , Sebastian Heeg

The search for other superconductors in the MgB2 class currently is focussed on Li{1-x}BC, which when hole-doped (concentration x) should be a metal with the potential to be a better superconductor than MgB2. Here we present the calculated…

Superconductivity · Physics 2009-11-07 J. M. An , H. Rosner , S. Y. Savrasov , W. E. Pickett

We studied the influence of sample preparation and defects in the superconducting properties samples using atomic ratios of Mg:B=1:1 and Mg:B=1:2. Samples were characterized by SEM, and XRD, and the magnetization properties were examined in…

We have performed polarized Raman scattering measurements on the newly discovered superconductor Ta$_{4}$Pd$_{3}$Te$_{16}$ ($T_c = 4.6$ K). We observe twenty-eight out of thirty-three Raman active modes, with frequencies in good accordance…

Superconductivity · Physics 2015-11-25 D. Chen , P. Richard , Z. -D. Song , W. -L. Zhang , S. -F. Wu , W. H. Jiao , Z. Fang , G. -H. Cao , H. Ding

We have performed polarized and temperature-dependent Raman scattering measurements on extremely large magnetoresitance compounds TaAs$_2$ and NbAs$_2$. In both crystals, all the Raman active modes, including six A$_g$ modes and three B$_g$…

We review recent development in Raman techniques and diamond anvil cell technology, that allow measurements of Raman of metals in the megabar pressure range. The Raman technique includes holographic transmission optics and single-stage…

The use of simple, fast and economic experimental tools to characterize low-dimensional materials is an important step in the process of democratizing the use of such materials in laboratories around the world. Raman spectroscopy has arisen…

We have performed polarized Raman scattering measurements on WTe$_2$, for which an extremely large positive magnetoresistance has been reported recently. We observe 5 A$_1$ phonon modes and 2 A$_2$ phonon modes out of 33 Raman active modes,…

Materials Science · Physics 2015-02-27 W. -D. Kong , S. -F. Wu , P. Richard , C. -S. Lian , J. -T. Wang , C. -L. Yang , Y. -G. Shi , H. Ding

Differently distorted areas on a polycarbonate sample are studied by means of Raman spectroscopy. The various Raman lines, whose energy shifts range between 200 and 3200 cm-1, are compared for different sample positions with respect to…

Materials Science · Physics 2012-03-02 J. Debus , D. Dunker

Polarized Raman scattering measurements have been performed on Na0.5CoO2 single crystal from 8 to 305 K. Both the A1g and E1g phonon modes show a softening below Tc1 ~ 83 K. Additionally, the A1g phonon mode, which is forbidden in the…

Strongly Correlated Electrons · Physics 2008-02-07 Q. M. Zhang , M. an , S. K. Yuan , Y. Wu , D. Wu , J. L. Luo , N. L. Wang , W. Bao , Y. N. Wang

Under homogeneous uniaxial strains, the Raman 2D band of graphene involving two-phonon double-resonance scattering processes splits into two peaks and they altogether redshift strongly depending on the direction and magnitude of the strain.…

Mesoscale and Nanoscale Physics · Physics 2015-03-19 Duhee Yoon , Young-Woo Son , Hyeonsik Cheong

We present a Raman scattering study of the E2g phonon anharmonicity and of superconductivity induced self-energy effects in MgB2 single crystals. We show that anharmonic two phonon decay is mainly responsible for the unusually large…

Superconductivity · Physics 2009-11-13 A. Mialitsin , B. S. Dennis , N. D. Zhigadlo , J. Karpinski , G. Blumberg

We investigate the influence of carbon-ion irradiation on the superconducting critical properties of MgB$_2$ thin films. MgB$_2$ films of two thicknesses viz. 400 nm (MB400nm) and 800 nm (MB800nm) were irradiated by 350 keV C ions having a…

Superconductivity · Physics 2019-01-30 Soon-Gil Jung , Seung-Ku Son , Duong Pham , Weon Cheol Lim , Jonghan Song , Won Nam Kang , Tuson Park

We investigated Raman spectra of single-layer and multi-layer graphene under ultraviolet laser excitation at the wavelength of 325 nm. It was found that while the G peak of graphene remains pronounced in UV Raman spectra, the 2D band…

Materials Science · Physics 2015-05-13 Irene Calizo , Igor Bejenari , Muhammad Rahman , Guanxiong Liu , Alexander A. Balandin

Within a two-band, strong coupling model we analyze SIS-tunneling conductance, Raman scattering and optical conductivity measured on $MgB_2$ samples. We find that features observed in tunneling and Raman spectroscopy at intermediate…

Superconductivity · Physics 2007-05-23 C. P. Moca , B. Janko

Frequency combs have revolutionized optical frequency metrology, allowing one to determine highly accurate transition frequencies of a wealth of molecular species. Despite a recognized scientific interest, these progresses have only…

We present results of our study of polarized Raman scattering and infrared reflectivity of rhombohedral ceramic La_1-ySr_yMn_1-xM_xO_3 manganites in the temperature range between 77 and 320K. In our samples, a part of the Mn atoms is…

Strongly Correlated Electrons · Physics 2009-11-11 A. Dubroka , J. Humlicek , M. V. Abrashev , Z. V. Popovic , F. Sapina , A. Cantarero

The buffer layer has been analysed by combined micro-Raman and micro-transmission experiments. The epitaxial graphene growth on the (0001) Si face of 6H-SiC substrates was tuned to get a mixed surface at the early stage of graphitization…

Mesoscale and Nanoscale Physics · Physics 2012-12-07 A. Tiberj , J. R. Huntzinger , N. Camara , P. Godignon , J. Camassel

Two--magnon Raman scattering is a useful tool to verify recent suggestions concerning the value of the interplanar exchange constant in antiferromagnetic two--layer systems, such as $YBa_2Cu_3O_{6+x}$. We present a theory for Raman…

Condensed Matter · Physics 2009-10-28 Dirk K. Morr , Andrey V. Chubukov , Arno P. Kampf , G. Blumberg