An overstoichiometric Nd–Fe–B hard magnetic material

0353549 - ÚFM 2011 RIV SR eng J - Journal Article
Žák, Tomáš - Talijan, N. - Ćosović, V. - Stajić-Trošić, J. - Grujić, A.
An overstoichiometric Nd–Fe–B hard magnetic material.
Journal of the Serbian Chemical Society. Roč. 75, č. 9 (2010), s. 1271-1277. ISSN 0352-5139. E-ISSN 0352-5139
R&D Projects: GA MŠMT 1M0512
Institutional research plan: CEZ:AV0Z20410507
Keywords : rapid quenched Nd–Fe–B * overstoichiometric Nd content * Mössbauer phase analysis * XRD * magnetic properties
Subject RIV: BM - Solid Matter Physics ; Magnetism
Impact factor: 0.725, year: 2010

A commercial Nd-rich Nd–Fe–B-based hard magnetic material was studied. The thermomagnetic curve showed clearly besides Curie points of the Nd2Fe14B phase and α-Fe also another critical temperature. Mössbauer (MS) phase analysis and X-ray diffraction analysis (XRD) showed in addition to the commonly known phases Nd2Fe14B and NdFe4B4 also some paramagnetic and ferromagnetic iron atoms (MS) and Fe17Nd2 intermetallics (XRD). During the exerted thermal treatment, the content of the Nd2Fe14B and NdFe4B4 phases remained almost unchanged, while iron atoms from remnant minor phases built a separate α-Fe phase. The XRD pattern also showed the presence of some minor Nd phase. The results of Squid measurements suggest a nanocrystalline decoupled structure of the Nd-rich alloy in the optimized magnetic state. Measurement of the magnetization loop showed, in spite of small changes in the phase composition, that magnetic properties of the quality material deteriorated during the thermal treatment.
Permanent Link: http://hdl.handle.net/11104/0192777