Atomic site occupancies and magnetic properties of Ni-doped FeAl intermetallic compounds

Neutron and X-ray powder diffraction revealed FeAl1-xNix alloys to have the B2(CsCl) structure with a virtually constant lattice parameter of 2.91 Ang strom and with the Ni atoms preferring the Fe sites. The annealed specimens showed paramagnetism for x < 0.20, superparamagnetism for x = 0.20, and fe rromagnetism for x > 0.25 whereas the rapidly solidified specimens showed s uperparamagnetism for x less than or equal to 10.20 and ferromagnetism for x greater than or equal to 0.25. The magnetization increased as the Ni conc entration (x) increased. The rapidly solidified specimens, in general, show ed stronger magnetic properties than the annealed ones. The magnetic proper ties were explained in terms of the local environmental model for magnetic atoms.