Suppression of anti-phase boundary defects in Mn-Al-Ti permanent magnets
Suppression of anti-phase boundary defects in Mn-Al-Ti permanent magnets
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DOI：
10.1016/j.actamat.2023.119646
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发表时间：
2023-12
期刊：
影响因子：
9.4
通讯作者：
Thomas Keller;Dylan Barbagallo;Tushar Kanti Ghosh;Natalya Sheremetyeva;G. Hautier;Ian Baker
中科院分区：
文献类型：
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作者：
Thomas Keller;Dylan Barbagallo;Tushar Kanti Ghosh;Natalya Sheremetyeva;G. Hautier;Ian Baker
基于锰的永磁体（pm）作为稀土永磁（repm）的替代品，在电动机和设备中显示出巨大的应用潜力。Mn-Al体系的亚稳铁磁τ相的磁性介于REPM Nd-Fe-B磁体和性能较低的铁氧体磁体之间。然而，Mn-Al pm的最大性能尚未达到其理论极限，部分原因是由于控制晶体缺陷（如反相边界（apb））方面的挑战。APBs作为Mn- al结构域反转的成核位点，通过中断l10排序，将Mn原子置于afm耦合的Mn-Mn构型中，从而对磁化产生负面影响。在本研究中，利用ab -初始化模型筛选三元元素，基于它们对APB的分离亲和力和它们对FM构型的偏好。三元元素加1 at。透射电镜观察到，% Ti降低了apb的密度。1在。通过保留hci和提高mr，观察到添加% Ti可以改善基体合金的（BH） maxmax。它还显著增加了τ相中孪晶界的比例。Ti的加入有效地抑制了基体在tcheating实验（nsamel行为）和高场VSM测量（spin-flop行为）中观察到的AFM行为。此外，Ti在550℃时热稳定，提高了τ相的可加工性。其他候选元素，Cr， V和Zr，在添加到Mn-Al中时具有类似的最小化apb的潜力。
Permanent magnets (PMs) based on manganese show significant potential for applications in electric motors and devices as an alternative to Rare-earth PMs (REPMs). The metastable ferromagnetic τ phase of the Mn-Al system has magnetic performance between the REPM Nd-Fe-B magnets and the lower performance ferrite magnets. However, the maximum performance in Mn-Al PMs has not reached its theoretical limit, in part due to challenges in controlling crystalline defects such as anti-phase boundaries (APBs). APBs act as nucleation sites for domain reversal in Mn-Al and negatively affect magnetization by interrupting the L10ordering, placing Mn atoms into AFM-coupled Mn-Mn configurations. In this study,Ab-initiomodeling was used to screen ternary elements based on their affinity to segregate to the APB and on their preference for FM configuration. The ternary element addition of 1 at.% Ti lowered the density of APBs as observed in a transmission electron microscope. The 1 at.% Ti addition was observed to improve(BH)maxover the base alloy, by preservingHciand improvingMr. It also significantly increased the fraction of twin boundaries in the τ phase. AFM behavior that was observed in the base alloy duringTCheating experiments (Néel behavior) and high-field VSM measurements (spin-flop behavior) was effectively suppressed with the addition of Ti. Additionally, the Ti addition thermally stabilizedHciat 550 °C, improving τ phase processability. Other candidate elements, Cr, V, and Zr, were modeled to have similar potential for minimizing APBs when added to Mn-Al.