PuPt ₂In ₇: A computational and experimental investigation

Flux-grown single crystals of PuPt ₂In ₇ are characterized and found to be both nonsuperconducting and nonmagnetic down to 2 K. The Sommerfeld specific heat coefficient of 250 mJ/mol K2 indicates heavy fermion behavior. We report the results of generalized gradient approximation (GGA)+U calculations of PuPt ₂In ₇ and as yet unsynthesized isovalent PuPt ₂Ga ₇. The strength of the c-f hybridization of PuPt ₂In ₇ is similar to the PuCoIn ₅ superconductor. The bare and f-weighted susceptibility within the constant-matrix-element approximation is calculated, showing a maximum along the q _z direction at q _x=q _y=0.5. A similar and slightly stronger maximum is also found in the structurally related heavy-fermion materials PuCoGa ₅ and PuCoIn ₅. The absence of superconductivity in PuPt ₂In ₇ is examined based on the results of our calculations.