The effect of compound addition Dy2O3 and Sn on the structure and properties of NdFeNbB magnets

• Published in: Journal of magnetism and magnetic materials Vol. 308; no. 1; pp. 80 - 84
• Main Authors: Li, Liya, Yi, Jianhong, Peng, Yuandong, Huang, Baiyun
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier Science 2007
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Exact sciences and technology; Magnetic properties and materials; Permanent magnets; Physics; Studies of specific magnetic materials; Grain boundaries; Curie point; Thermomagnetic effects; NdFeNbB permanent magnets; 75.50.Bb; Permanent magnets; Iron alloys; XRD; Neodymium alloys; 75.60.Ej; Alloying elements; Temperature performance; Temperature effects; Coercive force; Rare earth alloys; Microstructure; Grain refinement; Transition element alloys; Magnetic properties
• ISSN: 0304-8853
• DOI: 10.1016/j.jmmm.2006.05.005

NdFeNbB with the additions of Dy2O3 and Sn permanent magnets have been attained by means of powder-blending technique, and their magnetic properties, temperature performance and microstructure were studied in this paper. The addition of just 2.0 wt% Dy2O3 or 0.3 wt% Sn proved to be very effective in improving the permanent magnetic properties of NdFeNbB magnets. Dy2O3 additions result in the increase in the H(ci) and temperature dependence due to the increase of Tc, formation of (NdDy)-rich phase and grain refinement of Phi phase. This improvement of the coercivity stability of the magnets from the addition of Sn is attributed to the smoothing effect of the Sn addition at the grain boundaries. The magnetic properties, the temperature dependence and Curie temperature of NdFeNbB with Dy2O3 and Sn combined addition were found to be considerably improved. From the X-ray diffraction, SEM-EDAX studies and the thermo-magnetic study, the improved properties due to the solution of Dy and Sn to the Phi phase, the reduced N(eff) and the smaller Phi phase.