Superconductivity and non-Fermi liquid behavior near antiferromagnetic quantum critical points in CeRh1-xCoxIn5 -: art. no. 024551

Single crystals of CeRh1-xCoxIn5 have been investigated by means of specific heat measurements at zero pressure and electrical resistivity measurements under nearly hydrostatic pressure up to 28 kbar. Specific heat measurements for samples of CeRh1-xCoxIn5 with cobalt concentrations of x=0.65, 0.71, 0.77, 0.87, and 0.93 confirm the existence of antiferromagnetism for 0 <= x <= 0.7 and suggest the existence of a quantum critical point at x(c)similar to 0.75. Entropy versus x isotherms below similar to 5 K and the normalized residual resistivity rho(0 K)/rho(290 K) versus x curve both display maxima near x(c)similar to 0.75, suggesting further evidence for the existence and location of the quantum critical point. Electrical resistivity measurements under pressure for samples with x=0.1, 0.2, 0.4, and 0.6 reveal antiferromagnetism, pressure-induced superconductivity, and the coexistence of antiferromagnetism and superconductivity. Normalized residual resistivity rho(0 K)/rho(290 K) versus pressure P curves and the evolution of the power-law exponent n favor the existence of quantum critical points at critical pressures P(c)similar to 23 kbar, similar to 21 kbar, and similar to 7 kbar for samples with x=0.1, 0.2, and 0.4, respectively.