The effect of Ni doping on the electronic structure and superconductivity in the noncentrosymmetric ThCoC2

Abstract

ThCoC${}_2$ is a non-BCS, noncentrosymmetric superconductor with $T_c\simeq 2.5$~K, in which pairing mechanism was suggested to be either spin fluctuations or the electron-phonon coupling. Earlier experimental work revealed that $T_c$ can be greatly enhanced upon Ni doping in ThCo${}_{1-x}$Ni${}_x$C${}_2$, up to 12~K for $x=0.4$. In this work, using the Korringa-Kohn-Rostoker method with the coherent potential approximation (KKR-CPA), the evolution of the electronic structure upon Ni doping was studied and the increase of the density of states at the Fermi level was found. The electron-phonon coupling constant $\lambda$ was calculated using the rigid muffin tin approximation (RMTA) and the increase in $\lambda (x)$ was found. This indirectly confirms the electron-phonon coupling scenario as the trend in $\lambda (x)$ is in qualitative agreement with the experiment when the electron-phonon pairing is assumed.

5 pages, 4 figures, accepted in JMMM

References in corpus (7)

• Physical properties of the noncentrosymmetric superconductor Mg_10Ir_19B_16
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Cited by in corpus (1)

• Pressure effects on the electronic structure, phonons, and superconductivity of noncentrosymmetric ThCoC2