Magnetic Coupling in Pd-Dilute Iron Group Alloys

The magnetic properties of palladium and its alloys with iron group elements are discussed in terms of the splitting of the $d$ orbitals. The paramagnetic properties of pure palladium are accounted for on the basis that the holes in the $d$ shell are associated with the nonoverlapping $e$ orbitals, whereas the ferromagnetic coupling in the face-centered $3d$ elements and their alloys is associated primarily with holes in the overlapping $t$ orbitals. On this basis and on the basis of a change in the splitting when palladium is alloyed with $3d$ metals, it is possible to account for the paramagnetic and ferromagnetic properties of the Pd-dilute iron group alloys. Because of the larger amount of available data, attention is given primarily to the Pd-Fe system.