Magnetic properties of Fe₃Sn₂. II. Neutron diffraction study (and Mossbauer effect)

For pt.I see Act Crystallogr., vol.B32, p.1348 (1976). The intermetallic compound Fe3Sn2 has been studied by neutron diffraction and magnetisation measurements. This compound is ferromagnetic (TC=657K). At room temperature the spin direction is along the c axis. A spin rotation is observed between approximately 250 and 60K. Below 60K the spin direction lies in the (001) plane. A consistent fit of the neutron diffraction pattern is only obtained by a modification of the magnetic form factor of Shull and Yamada (1962). This modification means that the spin carriers are delocalised in the 'Fe-Sn' planes while they are localised along the c axis. The variations of the 57Fe anisotropic hyperfine fields (from Mossbauer effect measurements) and the mechanisms which predominantly determine the tin hyperfine fields in the series Fe3Sn-Fe3Sn2-FeSn are discussed.