Phase Formation and Magnetic Properties of La‐ and Ce‐Substituted (Nd1−2xRExPrx)2.28Fe13.58B1.14 Melt‐Spun Ribbons

Abstract

The effects of La and Ce substitution on phase formation and magnetic properties of (Nd1−2xRExPrx)2.28Fe13.58B1.14 (rare earth [RE] = La and Ce; x = 0.05 and 0.10, hereafter defined as La5Pr5, La10Pr10, Ce5Pr5, and Ce10Pr10) ribbons prepared via melt‐spinning technology are studied experimentally. According to the phase structure analysis of as‐cast alloys and melt‐spun ribbons, the as‐cast alloys are composed of the 2:14:1‐type main phase with the tetragonal Nd2Fe14B structure and α‐Fe minor phase, whereas the melt‐spun ribbons are a single 2:14:1‐type main phase, except for La5Pr5 ribbon with an additional α‐Fe minor phase. Based on magnetic measurements, the magnetic properties of La5Pr5, La10Pr10, Ce5Pr5, and Ce10Pr10 melt‐spun ribbons are determined. The remanence (Br), the coercivity (Hcj), and the maximum magnetic energy product ((BH)max) of La5Pr5 and La10Pr10 increase greatly, whereas Br and (BH)max of Ce5Pr5 and Ce10Pr10 decrease and Hcj of these two ribbons increases. Meanwhile, the Curie temperatures (Tc) of all the ribbons reduce with increasing La–Pr and Ce–Pr substitutions. In particular, La10Pr10 ribbon and Ce5Pr5 ribbon as Nd–Fe–B ribbons with La–Pr and Ce–Pr substitutions exhibit better magnetic properties.