Charge and spin density distributions in the ferromagnetic alloy Fe2B

The charge and spin density distributions in the ferromagnetic intermetallic compound Fe2B have been determined from x-ray and neutron scattering measurements. The results demonstrate significant deviations from spherical symmetry in the electronic configurations of the iron atoms. The x-ray scattering suggests that all the valence electrons of the boron atoms and one electron from each iron atom are non-localized. No evidence is found for absorption of electrons from boron into the iron 3d band. The neutron scattering results show that 15% of the magnetization is associated with non-localized electrons. A small negative magnetization found around the boron sites indicates some interaction between the iron 3d and boron 2sp bands.