Enhanced coercivity and grain boundary chemistry in diffusion-processed Ce13Fe79B8 ribbons

摘要

Ce13Fe79B8 ribbons were prepared by melt-spinning and diffusion-processing with minor amounts of Nd70Cu30 and Nd80Ag20 alloys. Low coercivities of similar to 0.2 T were obtained in the as-melt-spun ribbons and annealed ribbons although Ce-rich grain boundaries were observed. By diffusion process, the coercivity was increased to be over 0.7 T, due to the formation of magnetically hardened (Nd,Ce)(2)Fe14B shell. The chemistry of Ce-rich grain boundary phase was studied and face-center-cubic crystallographic structure was determined by nano-beam diffraction. The Henkel plots confirmed the enhanced magnetocrystalline anisotropy due to the formation of core/shell microstructure. (C) 2016 Elsevier B.V. All rights reserved.