XANES and XPS study of electronic structure of Ti-enriched Nd–Fe–B ribbons

Abstract

Electronic structure of rapidly quenched ribbons of nominal composition NdyFe(86-y-x)B14Tix (x= 0, 2, 4; y= 7, 8 at.%) was studied by X-ray absorption (Fe and Ti K-edge) and X-ray photoelectron spectroscopy. It was found by XANES that Ti addition promotes modifications of the electronic structure of Fe sub-band. From the analysis of differences in the pre-edges structure areas, coming from variations in the 3d density of states near the Fermi level, the evidences of acceptor nature of Ti and Fe atoms in NdFeB alloys are present. Using photoelectron spectroscopy, we found that neodymium, iron and titanium are in both, metallic and oxidized, states on the surface of the ribbons. A higher Ti0 content (at high vacuum) is characteristic of the annealed samples. The presence of oxidized titanium states was corroborated by XANES.