Nano-composite SmFe 7C x/α-Fe permanent magnet

Abstract

The structure, phase transformation and magnetic properties of the Sm 19Fe 67C 14 alloy prepared by mechanical alloying (MA) and subsequent re-milling have been studied systematically. With increasing re-milling time, the magnetic main phase, Sm 2Fe 14C (Nd 2Fe 14B-type structure), changes via a metastable SmFe 7C x phase (TbCu 7-type structure) to Sm-carbide (NaCl-type structure). Consequently, the easy magnetization direction changes from the basal phase for Sm 2Fe 14C to the c-axis for SmFe 7C x . The optimal values of M r/ M s=0.81 and ( BH) max=6.8 MGOe have been achieved for nano-composite SmFe 7C x /α-Fe permanent magnet.