We report the effects of the magnetic ground sate and microstructure on exchange bias (EB) in ball milled Ni₄₄Co₆Mn_39.5Sn_10.5 alloys. A giant bias field of 1.49 T has been obtained for the micron-sized particles after 15 h milling, which is considerably larger than that of 2 h milled platelets (0.35 T) and that of the bulk alloy (0.12 T). This giant bias field is attributed to the increased volume fraction of antiferromagnetic/ferromagnetic interface, the enhanced antiferromagnetic fraction and the formed agglomerates. Our results reveal the critical roles of the magnetic ground state and microstructure of milled alloys in determining EB.

我们报告了球磨Ni ₄₄ Co ₆ Mn _39.5 Sn _10.5合金中磁性研磨态和微观结构对交换偏压（EB）的影响。研磨15小时后，微米级颗粒获得了1.49 T的巨大偏置场，该偏置场比2 h研磨后的血小板（0.35 T）和块状合金（0.12 T）的偏置场大得多。该巨大的偏磁场归因于反铁磁/铁磁界面的体积分数增加，反铁磁分数增加和形成的附聚物。我们的研究结果揭示了铣削合金的磁性基态和微观结构在确定EB中的关键作用。