Chemical substitution study on magnetism and superconductivity in Ce$_{\mathrm{1-}}_{x}$Sm$_{x}$CoIn$_{\mathrm{5}}$.

We report electrical resistivity, magnetization, and specific heat measurement measurements on the Ce$_{\mathrm{1-}}_{x}$Sm$_{x}$CoIn$_{\mathrm{5}}$ system for 0 $\le \quad x$ $\le $ 1. Superconductivity in CeCoIn$_{\mathrm{5}}$ is suppressed with increasing Sm concentrations up to $x \quad =$ 0.1, above which there is no evidence for superconductivity from measurements down to 50 mK; antiferromagnetic ordering in SmCoIn$_{\mathrm{5}}$ persists deep into the Ce-rich side, and is not completely suppressed until $x \quad =$ 0.25. We have observed the development of a low-temperature upturn in electrical resistivity for 0.70 $\le \quad x \quad \le $ 0.85 which is consistent with behavior for a single-ion impurity Kondo effect and suggests that the substitution of Sm for Ce causes a change of the relative strength of competing Kondo and Ruderman-Kittel-Kasuya-Yosida energy scales.