F-electron localized/itinerant crossover in ACoGa5 (A=U, Np, Pu, Am)

Abstract

Measurements of magnetic susceptibility, specific heat, and electrical resistivity have been performed on the ACoGa5 (A=U, Np, Pu, Am) series. The electrical resistivity of UCoGa5 and PuCoGa5 can be scaled upon the ρ(T) data of the heavy-fermion superconductor CeCoIn5 indicating a single spin fluctuation energy scale dominates the transport properties. The physical properties of the ACoGa5 materials suggest the PuCoGa5 superconductor resides near an itinerant/localized crossover of the 5f electrons and is remarkably similar to the one that occurs in the light actinide elements. © 2006 The Physical Society of Japan.