The role of carbon for superconductivity in MgC${}_x$Ni${}_3$ from specific heat

Abstract

The influence of carbon deficiency on superconductivity of MgCNi${}_3$ is investigated by specific heat measurements in the normal and superconducting state. In order to perform a detailed analysis of the normal state specific heat, a computer code is developed which allows for an instantaneous estimate of the main features of the lattice dynamics. By analyzing the evolution of the lattice vibrations within the series and simultaneously considering the visible mass enhancement, the loss in the electron-phonon coupling can be attributed to significant changes of the prominent Ni vibrations. The present data well supports the recently established picture of strong electron-phonon coupling and ferromagnetic spin fluctuations in this compound.

arXiv comment4 pages, latex, corrections to the text, one reference added, one figure corrected

References in corpus (12)

• Superconductivity Near Ferromagnetism in MgCNi3
• Superconductivity and Electronic Structure of Perovskite MgCNi3
• (13)C NMR investigation of the superconductor MgCNi_3 up to 800K
• Evidence for strong electron-phonon coupling in MgCNi_3
• Carbon Concentration Dependence of the Superconducting Transition Temperature and Structure of MgCxNi3
• Superconductivity near the vibrational mode instability in MgCNi3
• Carbon isotope effect in superconducting MgCNi_3
• Influence of Carbon Concentration on the Superconductivity in MgCxNi3
• Electronic Structure of ZnCNi3
• Pressure effects on the Tc of superconducting MgCxNi3
• X-ray absorption and optical spectroscopy studies of (Mg${}_{1-x}$Al${}_x$)B${}_2$
• Role of C in MgC_xNi_3 investigated from first principles

Cited by in corpus (7)

• Strong electron-phonon coupling in the rare-earth carbide superconductor La2C3
• Theoretical search for superconductivity in Sc3XB perovskites and weak ferromagnetism in Sc3X (X = Tl, In, Ga, Al)
• S-wave superconductivity probed by measuring magnetic penetration depth and lower critical field of MgCNi${}_3$ single crystals
• Weak inter-band coupling in Mg${}^{10}$B${}_2$: a specific heat analysis
• Effect of Boron substitution on the superconductivity of non-oxide perovskite MgCNi3
• Crystal growth and characterization of the antiperovskite superconductor MgC1-xNi3-y
• Superconductivity in the vicinity of ferromagnetism in oxygen free perovskite MgCNi3: An experimental and DFT (Density Functional Theory) study