Strong electron-phonon coupling in the rare-earth carbide superconductor La2C3

Abstract

We present the results of a crystal structure determination using neutron powder diffraction as well as the superconducting properties of the rare-earth sesquicarbide La2C3 (Tc ~ 13.4 K) by means of specific heat and upper critical field measurements. From the detailed analysis of the specific heat and a comparison with ab-initio electronic structure calculations, a quantitative estimate of the electron-phonon coupling strength and the logarithmic average phonon frequency is made. The electron-phonon coupling constant is determined to λ~ 1.35. The electron-phonon coupling to low energy phonon modes is found to be the leading mechanism for the superconductivity. Our results suggest that La2C3 is in the strong coupling regime, and the relevant phonon modes are La-related rather than C-C stretching modes. The upper critical field shows a clear enhancement with respect to the Werthamer-Helfand-Hohenberg prediction, consistent with strong electron-phonon coupling. Possible effects on the superconducting properties due to the noncentrosymmetry of the crystal structure are discussed.

12 pages, 11 figures, submitted to Phys. Rev. B

References in corpus (26)

• Heavy fermion superconductivity and magnetic order in non-centrosymmetric $CeP{t}_{3}Si$
• Superconductivity in the Intercalated Graphite Compounds C6Yb and C6Ca
• Superconductivity of bulk CaC6
• S-wave/spin-triplet order in superconductors without inversion symmetry: Li${}_2$Pd${}_3$B and Li${}_2$Pt${}_3$B
• Two-gap superconductivity in MgB${}_2$: clean or dirty?
• CePt3Si: an unconventional superconductor without inversion center
• Superconducting phase diagram of Li Metal in nearly hydrostatic pressures up to 67 GPa
• Band filling and interband scattering effects in MgB${}_2$: C vs Al doping
• Superconductivity in lithium, potassium and aluminium under extreme pressure: A first-principles study
• Line nodes in the superconducting gap function of noncentrosymmetric CePt_3Si
• Superconductivity and Lattice Instability in Compressed Lithium from Fermi Surface Hot Spots
• Order parameter in superconductors with non-degenerate bands
• Crystal Symmetry, Electron-Phonon Coupling, and Superconducting Tendencies in Li${}_2$Pd${}_3$B and Li${}_2$Pt${}_3$B
• Field dependence of the zero energy density of states around vortices in an anisotropic gap superconductor
• Specific Heat of the Ca-Intercalated Graphite Superconductor CaC${}_6$
• Carbon Concentration Dependence of the Superconducting Transition Temperature and Structure of MgCxNi3
• Evidence for strong electron-phonon coupling in MgCNi_3
• {\em Ab Initio} Calculations of ${\mathbf{H}}_{c2}$ in Type-II Superconductors: Basic Formalism and Model Calculations
• Electronic Structure of ZnCNi3
• Muon-spin-rotation measurements of the penetration depth in Li_2Pd_3B
• Multigap Superconductivity in Y${}_2$C${}_3$: A ${}^{13}$C-NMR Study
• Electronic Structure and Electron-Phonon Coupling in the 18K Superconductor Y2C3
• Structural properties of the sesquicarbide superconductor La2C3 at high pressure
• Role of C in MgC_xNi_3 investigated from first principles
• The role of carbon for superconductivity in MgC${}_x$Ni${}_3$ from specific heat
• Are Th doped Y2C3 and La2C3 two-band superconductors?

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