Nano-composite SmFe7Cx/α-Fe permanent magnet

Abstract The structure, phase transformation and magnetic properties of the Sm19Fe67C14 alloy prepared by mechanical alloying (MA) and subsequent re-milling have been studied systematically. With increasing re-milling time, the magnetic main phase, Sm2Fe14C (Nd2Fe14B-type structure), changes via a metastable SmFe7Cx phase (TbCu7-type structure) to Sm-carbide (NaCl-type structure). Consequently, the easy magnetization direction changes from the basal phase for Sm2Fe14C to the c-axis for SmFe7Cx. The optimal values of Mr/Ms=0.81 and (BH)max=6.8 MGOe have been achieved for nano-composite SmFe7Cx/α-Fe permanent magnet.