Magnetic and Microstructural Characteristics of Nd-Fe-B Sintered Magnets Doped With Dy2O3 and DyF3 Powders

Abstract

Magnetic and microstructural properties of (Nd-26.06, Dy-6.51)-Fe-bal.-B-0.97-M-2.39 (wt.%) (M = Cu, Al, Co, and Nb) sintered magnets doped with Dy2O3 and DyF3 powders were studied. In the case of the Dy2O3-doped magnet, Dy was distributed along the near grain boundaries. In contrast, the DyF3-doped magnet and the undoped magnet showed that Dy was distributed uniformly in the main phase. The coercivity and the remanence of the Dy2O3 ff and DyF3-doped magnets were 33.2 kOe, 11.64 kG, and 34.5 kOe, 11.21 kG, respectively. The coercivity of the DyF3-doped magnet was the largest but its remanence was the smallest among other magnets because the Dy was distributed throughout the main phase. Uniform distribution of the Dy in the DyF3-doped magnet was probably due to their lower bonding energy and higher chemical potential for diffusion.