Conditions for magnetism in Pu systems

Abstract Weakly paramagnetic character of δ-Pu is preserved when Pu is doped by Am, which expands the crystal lattice. Specific-heat data show that the γ -coefficient does not increase. Such behaviour can be understood on the basis of LSDA+U calculations, which yield invariably non-magnetic Pu state due to the proximity to the 5f 6 state. We suggest that a general condition for Pu magnetism is some degree of a hybridization with states of other elements in alloys and compounds, which allows for the reduction of the 5f count.