Variation of the effective exchange parameter across 3d-transition-metal series -: art. no. 10A317

The so-called effective exchange parameter J(0) of the classical Heisenberg Hamiltonian for magnetic interactions is investigated as a function of volume and occupation of the valence band across 3d-transition-metal series in face-centered-cubic (fcc) metals, from Mn to Ni. We show that there exists a particular area in the volume-electron concentration phase space, where the effective exchange parameter behaves anomalously. The peculiarity, in combination with deviations of the electronic structure in real alloys from the rigid-band behavior, should lead to highly frustrated magnetic configurations that were predicted theoretically for the fcc Invar alloys. (c) 2005 American Institute of Physics.