Thermodynamic and transport investigation ofCeCoIn5−xSnx

Abstract

Measurements of specific heat, magnetic susceptibility, electrical resistivity, and penetration depth have been performed on $\mathrm{Ce}\mathrm{Co}{\mathrm{In}}_{5\ensuremath{-}x}{\mathrm{Sn}}_{x}$ $(0\ensuremath{\leqslant}x\ensuremath{\leqslant}0.24)$ single crystals. The suppression of superconductivity and the decrease of the specific heat jump at ${T}_{c}$, $\ensuremath{\Delta}C∕{T}_{c}$, with increasing Sn concentration, and the power-law temperature dependence of penetration depth are consistent with impurity scattering calculated within the Abrikosov-Gorkov formalism indicating $d$-wave superconductivity in $\mathrm{Ce}\mathrm{Co}{\mathrm{In}}_{5\ensuremath{-}x}{\mathrm{Sn}}_{x}$. The non-Fermi liquid behavior [$C∕T\ensuremath{\sim}\ensuremath{-}\mathrm{ln}\phantom{\rule{0.2em}{0ex}}T$ and $\ensuremath{\rho}(T)\ensuremath{\sim}T$] observed in the normal state in zero magnetic field is quite robust against Sn substitution (and a variety of other tuning parameters), suggesting quantum criticality involving itinerant $f$-electrons in this system.