Sperimagnetism in Fe78Er5B17 and Fe64Er19B17 metallic glasses: II. Collinear components and ferrimagnetic compensation

Magnetization measurements on an Fe(64)Er(19)B(17) glass and polarized-beam neutron scattering measurements on Fe(78)Er(5)B(17) and Fe(64)Er(19)B(17) were described in part I. The finite spin-flip neutron scattering cross sections were calculated using a sperimagnetic structure based on random cone arrangements of the magnetic moments. The temperature variation of the cross sections of Fe(64)Er(19)B(17) suggested that a compensated sperimagnetic phase existed at T(comp).The analysis of the non-spin-flip neutron scattering cross sections is described here in part II. Two spin-dependent total structure factors S(±±)(Q) were defined from these cross sections and, despite the limited range of the data 0.5 Å(-1) < Q < 6.5 Å(-1), their Fourier transform gave reliable spin-dependent radial distribution functions RDF(±±)(r). These were interpreted in terms of the atomic pair correlation functions ρ(±±)(AB)(r) and their weighting factors ω(±±)(AB). The data on Fe(64)Er(19)B(17) at 1.5 K showed, for example, how the directions of the magnetic sublattices can be defined uniquely. The analysis of the RDF(±±)(r) for Fe(64)Er(19)B(17) at 112 K confirmed that the mean collinear components of the magnetic moments , are zero on both sublattices in the compensated sperimagnetic structure at T(comp). The pre-peak in the spin-dependent total structure factors at 112 K showed that it originated in the atomic structure and it may involve Fe-Er-Fe 'collineations' at a radial distance of ≈6.0 Å. Finally, the RDF(±±)(r) of Fe(64)Er(19)B(17) at 180 K and of Fe(78)Er(5)B(17) at 2 K show that both glasses have the (μ(Fe) UP:μ(Er) DOWN) structure like the (Fe,Tb)(83)B(17) collinear ferrimagnets.