NdFeB Permanent Magnets with Various Nd Content

摘要

Three kinds of commercial Nd-Fe-B based materials were compared using ~(57)Fe Moessbauer spectroscopy and X-ray analysis: near the Nd_2Fe_(14)B stoichiometry and with both lowered and raised Nd content. Magnetically hard Nd_2Fe_(14)B is present in all three materials. In the Nd-low material it is accompanied with the magnetically soft Fe_3B phase, building the nanocom-posite 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 Nd_(1.1)Fe_4B_4 one.