Improvement of the microstructure and magnetic properties of (La,Ce)–Fe–B nanocrystalline ribbons

Abstract

Obstacles of the inferior microstructure and poor magnetic properties of (La, Ce)-Fe-B type magnet are on the way to expanding its application fields. In this work, (La, Ce)-Fe-B melt-spun ribbons have been prepared with different La/Ce ratios and rare earth content. The microstructure and magnetic properties of ribbons have been investigated. With La/Ce ratio increased, the fraction of the CeFe2 phase decreased, and the β-La phase segregated among matrix grains, which deteriorates the coercivity of ribbons. Reducing rare earth content would effectively suppress the β-La phase and improve the proportion of the matrix phase in ribbons. Here, the optimal alloy composite (La15Ce85)14Fe80B6 has been obtained with modified microstructure and inhibited secondary phases. A good ribbon performance has been tested with H cj = 4.51 kOe, B r = 6.29 kGs, and (BH)max = 6.81 MGOe.