Heavy-fermion, magnetic and superconducting behavior of (Ce,M)Cu2Si2; M = Y, La, Th

Ce1-xMxCu2Si2 with M=Y, La, and Th have been studied via lattice constants, DC and AC magnetic susceptibility and specific heat. Y doping leads to a monotonic depression of the electronic specific-heat coefficient γ, while La substitution causes an initial decrease of γ followed by an increase for x>0.5. Antiferromagnetic order occurs for M = Th and x≥0.1 and a more complex type behavior is observed for x=0.9. Magnetism and superconductivity coexist between x=0.1 and 0.3 in Th-doped samples. (orig.)