NdFeB permanent magnets with various Nd content

Abstract

Three kinds of commercial Nd-Fe-B based materials were compared using 57Fe Mössbauer spectroscopy and X-ray analysis: near the Nd 2Fe14B stoichiometry and with both lowered and raised Nd content. Magnetically hard Nd2Fe14B is present in all three materials. In the Nd-low material it is accompanied with the magnetically soft Fe3B phase, building the nanocomposite structure. In the Nd-rich sample the overstoichiometric Nd atoms seem to build separate phase of Fe-Nd solid solution. None of the materials contain significant content of phases degrading magnetic characteristics, with except of minor Nd1.1Fe 4B4 one.