Cohesive Properties of 3d Transition Metal Alloys

The formation energy, the deviation of the lattice parameter from Vegard's law and the bulk modulus of Fe-base and Ni-base 3d transition metal alloys, are calculated on the basis of the two-band model and the virial theorem. The results are in good agreement with the experimental values and are interpreted with three important factors i.e. the d-d bonding effect, the s-d charge transfer effect and the magnetic effect due to the changes of the magnitudes of the local magnetic moments. Especially, it is verified numerically that the magnetovolume effect in many 3d alloys is described by the approximate magnetic pressure which is equal to a linear combination of the squares of the local moments.