Perpendicularly magnetized Co-based Heusler alloys are promising candidates in high-performance spintronic devices. However, there is a contradiction between thermal stability and damping-like spin–orbit torque (SOT) efficiency in Co-based Heusler alloys with interface-induced perpendicular magnetic anisotropy (PMA). Here, we present epitaxially grown perpendicularly magnetized Mn1+xCo2−xAl (MCA) Heusler alloys through tetragonal distortion. Ferrimagnetism and distortion-induced PMA are obtained in MCA Heusler alloys. A large effective spin Hall angle (θeff) up to 0.33 is experimentally demonstrated in Pt/MCA bilayers, markedly surpassing that in conventional Pt/FM bilayers. Consequently, SOT-induced efficient magnetization switching is realized in Pt/MCA bilayers, with a critical switching current density (Jc) as low as 4 × 107 A/cm2. The large θeff and high SOT efficiency would be attributed to the staggered magnetic exchange torques in the ferrimagnetic MCA Heusler alloys. These findings demonstrate that perpendicularly magnetized ferrimagnetic MCA Heusler alloys are highly promising for high-density SOT-magnetic random-access memory with superior thermal stability and low power consumption.

中文翻译：

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垂直磁化 Mn1+xCo2−xAl Heusler 合金中自旋轨道扭矩引起的高效磁化翻转


垂直磁化的钴基霍斯勒合金是高性能自旋电子器件的有希望的候选者。然而，具有界面诱导垂直磁各向异性（PMA）的钴基霍斯勒合金的热稳定性和类阻尼自旋轨道扭矩（SOT）效率之间存在矛盾。在这里，我们提出了通过四方畸变外延生长的垂直磁化 Mn1+xCo2−xAl (MCA) Heusler 合金。 MCA Heusler 合金中具有亚铁磁性和畸变诱导 PMA。实验证明 Pt/MCA 双层的有效自旋霍尔角 (θeff) 高达 0.33，明显超过传统 Pt/FM 双层。因此，在 Pt/MCA 双层中实现了 SOT 诱导的高效磁化开关，临界开关电流密度 (Jc) 低至 4 × 107 A/cm2。大 θeff 和高 SOT 效率归因于亚铁磁 MCA Heusler 合金中交错的磁交换扭矩。这些发现表明，垂直磁化的亚铁磁 MCA Heusler 合金具有优异的热稳定性和低功耗，对于高密度 SOT 磁性随机存取存储器非常有前景。