Temperature vs. Sm concentration phase diagram and quantum criticality in the correlated electron system Ce1-xSmxCoIn5
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We report electrical resistivity, magnetization, and specific heat measurements on the correlated electron system Ce1−xSmxCoIn5 (0≤x≤1). Superconductivity (SC) in the heavy-fermion compound CeCoIn5, which is suppressed with increasing Sm concentration x, and antiferromagnetic (AFM) order of SmCoIn5, which is suppressed with decreasing x, converge near a quantum critical point at xQCP≈0.15, with no indication of coexistence of SC and AFM in the vicinity of the QCP. Non-Fermi-liquid (NFL) behavior is observed in the normal-state electrical resistivity, ρ(T), and specific heat, C(T), in the vicinity of the QCP; e.g., the coefficient and the exponent of the power-law T dependence of ρ(T) exhibit pronounced maxima and minima, respectively, at xQCP, while C(T)/T exhibits a logarithmic divergence in T at xQCP. A low-temperature upturn in ρ(T) develops in the range 0.70≤x≤0.85 which is reminiscent of a single impurity Kondo effect, suggesting that Sm substitution tunes the relative strength of competing Kondo and Ruderman-Kittel-Kasuya-Yosida energy scales. The suppression of SC with increasing x is probably associated with the exchange interaction between the Ce quasiparticles involved in the superconductivity and the magnetic moments of the Sm ions.
Pouse, N., Jang, S., White, B. D., Ran, S., Adhikari, R. B., Almasan, C. C., & Maple, M. B. (2018). Temperature versus Sm concentration phase diagram and quantum criticality in the correlated electron system Ce1−xSmxCoIn5. Physical Review B, 97(23). https://doi.org/10.1103/physrevb.97.235149
Physical Review B
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