FIELD-INDUCED MAGNETISM IN ACTINIDE SYSTEMS

We demonstrate that the field-induced spin and orbital moments in para magnetic metals in general are parallel, regardless of the filling of the electronic shell. The early actinides, however, approach the borde r where the moments go antiparallel. This results in peculiar magnetic states for alpha-Pu and some uranium compounds, where the spin moment s are antiparallel to the applied field and the magnetic response is d ominated by the orbital contribution, and consequently these systems d isplay unusual spin densities and magnetic form factors.