Magnetic Properties of the Pd3Mn2 Alloy

The structure, magnetic properties and thermal properties of the ζ-phase and µ-phase of the Pd 3 Mn 2 alloy were investigated. The ζ-phase has a b.c.t. lattice with the CsCl-type superstructure, while the µ-phase has a modified form of the ζ-phase superstructure. Both phases are antiferromagnetic, but in the µ-phase the susceptibility below the Néel point is strongly dependent on the field strength. The excess heat absorption at the Néel point is 510 cal./mol. (Pd 15 Mn) for the µ-phase, 890 cal./mol. (Pd 15 Mn) for the ζ-phase, and the heat of transformation from µ to ζ is 180 cal./mol. (Pd 0.6 Mn 0.4 ) These results are discussed on the basis of the two sublattice model of an antiferromagnet.