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

Abstract

Magnetization measurements on an Fe64Er19B17 glass and polarized-beam neutron scattering measurements on Fe78Er5B17 and Fe64Er19B17 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 Fe64Er19B17 suggested that a compensated sperimagnetic phase existed at Tcomp. 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 and their weighting factors . The data on Fe64Er19B17 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 Fe64Er19B17 at 112 K confirmed that the mean collinear components of the magnetic moments , are zero on both sublattices in the compensated sperimagnetic structure at Tcomp. 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 Fe64Er19B17 at 180 K and of Fe78Er5B17 at 2 K show that both glasses have the (μFe UP:μEr DOWN) structure like the (Fe,Tb)83B17 collinear ferrimagnets.