Study of Nd-Fe-B Alloys with Nonstoichiometric Nd Content in Optimal Magnetic State

0339967 - ÚFM 2010 RIV SR eng J - Journal Article
Ćosović, V. - Talijan, N. - Grujić, A. - Stajić-Trošić, J. - Žák, Tomáš - Lee, Z. - Radmilović, V.
Study of Nd-Fe-B Alloys with Nonstoichiometric Nd Content in Optimal Magnetic State.
Science of Sintering. Roč. 41, č. 2 (2009), s. 211-220. ISSN 0350-820X
R&D Projects: GA MŠMT 1M0512
Institutional research plan: CEZ:AV0Z20410507
Keywords : Rapid quenched Nd-Fe-B alloys * Nonstoichiometric Nd content * Phase composition * Grain size * Magnetic properties
Subject RIV: BM - Solid Matter Physics ; Magnetism
Impact factor: 0.486, year: 2009

Characterization of two rapid-quenched Nd-Fe-B alloys with nonstoichiometric Nd content in the optimized magnetic state was carried out using the X-ray diffractometry (XRD), Fe-57 Mossbauer spectroscopic phase analysis (MS), electron microscopy (TEM), high resolution TEM (HREM) and Superconducting Quantum Interference Device (SQUID) magnetometer. The alloy with the reduced Nd content (Nd4.5Fe77B18.5) was found to have the nanocomposite structure of Fe3B/Nd2Fe14B and partly alpha-Fe/Nd2Fe14B, with mean grain size below 30 nm. On the other side, the overstoichiometric Nd14Fe79B7 alloy has almost a monophase structure with the dominant content of the hard magnetic phase Nd2Fe14B (up to 95 wt. %) and a mean crystallite size about 60 nm, as determined by XRD and TEM analysis. The results of magnetic measurements on SQUID magnetometer also suggest the nanocomposite structure of the Nd-low alloy and nanocrystalline decoupled structure of the Nd-rich alloy after the optimal heat treatment.
Permanent Link: http://hdl.handle.net/11104/0183324