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.

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

References in corpus (1)

• Evidence for strong electron-phonon coupling in MgCNi_3

Cited by in corpus (5)

• 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)
• 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