Coexistence of superconductivity and antiferromagnetism in CeRh1-xCoxIn5 -: art. no. 014506

Single-crystal specimens of CeRh1-xCoxIn5 have been investigated by means of specific heat, electrical resistivity, and magnetic susceptibility, measurements as a function of temperature. The measurements repeal the occurrence of superconductivity in compounds with 0.4less than or equal toxless than or equal to1.0 with superconducting transition temperatures between similar to1 and 2 K and antiferromagnetic order in compounds with 0.2less than or equal toxless than or equal to0.6 with Neel temperatures between similar to3 and 4 K, Superconductivity and anti ferromagnetism appear to coexist fur concentrations in the range 0.4less than or equal toxless than or equal to0.6. Specific-heat measurements indicate that the total entropy under the superconducting and antiferromagnetic transitions is comparable for the samples with 0less than or equal toxless than or equal to0.8, which implies that the same electrons are participating in the two phenomena. Measurements of the ac magnetic susceptibility revealed superconducting transitions in single-crystal specimens of CeRhIn5 at T-c=0.09 K. but the superconductivity was suppressed when the samples were powdered.