Site occupancy of Zr in Nd(FeZr)B magnet during hydrogenation disproportionation desorption recombination process

Abstract

In order to elucidate the role of Zr addition for the evolution of magnetic anisotropy in hydrogenation disproportionation desorption recombination treated NdFeB magnets, Zr site occupancy in Nd16Fe75.5Zr0.5B8 alloy has been investigated by means of x-ray absorption fine structure. Zr is found to occupy preferably the Fe(j2) sites in the Nd2Fe14B structure for the as-cast state and keeps this position in the disproportionated stage. Zr(j2) sites are situated at the position connecting two Fe-hexagonal nets where strong Fe–Zr bondings stabilize Nd2Fe14B structure against disproportionation.

Effect of Mn on the magnetic properties of Fe3B/Nd2Fe14B nanocomposites

“…This could be due to the fact that the 8j 1 site has a maximum number of three 8j 2 near neighbors and Mn occupies 8j 2 Fe sites affecting the local magnetic moments there, which results in the decrease of the H hf of 8j 1 site. It may be concluded that Mn has a site preference for the 8j 2 in the Nd 2 Fe 14 B phase [9,26]. …”

Bond lengths inGe1−xSixcrystalline alloys grown by the Czochralski method

“…A Si͑111͒ double-crystal monochromator was used to define the x-ray energy. 13 K-edge XAFS of the GeSi alloys were measured in transmission mode at 20 K together with a comparison of that for pure-Ge single crystal. The incident and transmitted x-ray intensities were monitored simultaneously by two ionization chambers.…”

Site preferences of Zr and Ga during the HDDR process for Nd2Fe14BNd2Fe14B-based magnets by XAFS

“…Moreover recent XAFS theory can predict an exact XAFS spectrum based on the first principle theory. We have engaged the determination of the site occupancy for the additives such as Zr, Ga and Nb in the hydrogenation, disproportionation, desorption and recombination (HDDR) process of the Nd 2 Fe 14 B-based magnets [1][2][3][4]. The application of the HDDR process to Nd 2 Fe 14 Bbased magnets enhances BH max due to the grain refinement [5].…”