Tuning of the electronic properties in PuCoGa5 by actinide (U, Np) and transition-metal (Fe, Rh, Ni) substitutions -: art. no. 104508

The physical properties of An-substituted (An=U, Np) and T-substituted (T=Fe, Rh, Ni) PuCoGa5 have been studied by magnetization, specific heat, and electrical resistivity. In all cases, the superconducting critical parameters decrease with substitution and different trends emerge. Isoelectronic substitution is the least destructive for superconductivity. On the contrary, for nonisoelectronic substitution, the T-c decrease versus c/a does not follow the trend observed in the cerium and plutonium isostructural compounds. Substituting Pu with actinides most dramatically affects the critical parameters. In particular, superconductivity is predicted to vanish in PuCoGa5 with 18% Np substitution, making the coexistence of superconductivity and magnetism unlikely in a (Pu1-xNpx)CoGa5 system. The electron count in AnTGa(5) compounds appears as a general and plausible quantity to evaluate trends in the variation of the critical (T-c, H-c2(0)) and electronic (gamma) parameters.