2003/12/18 by T. Masui, S. Lee, S. Tajima · 4 citations
Chemistry · Materials Science · Mathematics · Physics and Astronomy · #Analytical Chemistry (journal) #Anisotropy #Carbon fibers #Chemistry #Computer science #Condensed matter physics #Coupling (piping) #Crystallography #Electrical resistivity and conductivity #Geometry #Materials science #Mathematics #Optics #Physics #Physics of Superconductivity and Magnetism #Plane (geometry) #Raman scattering #Raman spectroscopy #Scattering #Substitution (logic) #Superconductivity in MgB2 and Alloys #Thermal Expansion and Ionic Conductivity #cond-mat.supr-con
paper · pdf · doi:10.1103/physrevb.70.024504
published as Phys. Rev. B 70, 024504 (2004) · 6 pages, 8 figures
arxiv created 2003/12/18 · openalex publication_date 2004/07/13 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
The electronic properties of the carbon-substituted MgB2 single crystals are reported. The carbon substitution drops Tc below 2\phantom\rule0.3em0exK. In-plane resistivity shows a remarkable increase in residual resistivity by C substitution, while the change of in-plane/out-of-plane Hall coefficients is rather small. Raman scattering spectra indicate that the E2g-phonon frequency radically hardens with increasing the carbon content, suggesting the weakening of electron-phonon coupling. Another striking C effect is the increases of the second critical fields in both in-plane and out-of-plane directions, accompanied by a reduction in the anisotropy ratio. The possible changes in the electronic state and the origin of Tc suppression by C substitution are discussed.