L10 rare-earth-free permanent magnets: The effects of twinning versus dislocations in Mn-Al magnets

Abstract

Defects of various kinds play a crucial role on coercivity in rare-earth-free permanent magnetic alloys with L10 structure. In this work, the negative effect of twin structure and the positive effect of dislocations on the coercivity are clarified in a systematic experimental study of L10-MnAl alloys, because the former defect can induce the nucleation of reversal domain and the latter can act as a pinning center. Thus, the combination of eliminating twin structure and introducing high-density dislocations could overcome the present bottleneck in magnetic performance. This work may inspire avenues for the development of L10 rare-earth-free permanent magnetic alloys.