AI 中文总结
该研究通过Pt双层异质结构实验，证实自旋霍尔磁电阻可探测反铁磁自旋结构，发现α-Fe₂O₃/Pt的SMR振幅达2.5E-3，为室温反铁磁自旋电子学提供了潜力大的候选体系。
AI 中文摘要
反铁磁材料在自旋电子学应用中有望提升性能，因为它们相比铁磁体更能抵御外部磁场扰动，且磁化动力学更快。然而，由于缺乏宏观磁化强度，反铁磁态的直接观测颇具挑战性。我们通过研究具有Pt重金属顶电极的双层异质结构中的易平面反铁磁绝缘体α-Fe₂O₃（赤铁矿）和NiO，证明自旋霍尔磁电阻（SMR）是一种可通过简单电学输运实验探测反铁磁自旋结构的通用工具。在三个正交平面内旋转外部磁场时，我们记录了Pt的纵向和横向电阻率，观测到与SMR效应一致的特征电阻率调制。我们分析了这些调制的振幅和相位，并将数据与典型共线亚铁磁体Y₃Fe₅O₁₂/Pt双层的结果进行比较。观测到的磁场依赖性由基于两个磁亚晶格并考虑磁场诱导的畴结构变化的综合模型解释。我们的结果表明，SMR效应可用于读出自旋构型并研究反铁磁多畴材料中的磁弹性效应。我们证明，SMR振幅在亚铁磁体和反铁磁体中均与亚晶格磁化强度绝对值之和成正比。在α-Fe₂O₃/Pt双层中，我们发现SMR振幅高达2.5E-3，是典型Y₃Fe₅O₁₂/Pt双层的两倍，使该系统对室温反铁磁自旋电子学应用极具吸引力。
英文摘要
Antiferromagnetic materials promise improved performance for spintronic applications, as they are robust against external magnetic field perturbations and allow for faster magnetization dynamics compared to ferromagnets. The direct observation of the antiferromagnetic state, however, is challenging due to the absence of a macroscopic magnetization. We show that the spin Hall magnetoresistance (SMR) is a versatile tool to probe the antiferromagnetic spin structure via simple electrical transport experiments by investigating the easy-plane antiferromagnetic insulators alpha-Fe2O3 (hematite) and NiO in bilayer heterostructures with a Pt heavy-metal top electrode. While rotating an external magnetic field in three orthogonal planes, we record the longitudinal and the transverse resistivities of Pt and observe characteristic resistivity modulations consistent with the SMR effect. We analyze both their amplitude and phase and compare the data to the results from a prototypical collinear ferrimagnetic Y3Fe5O12/Pt bilayer. The observed magnetic field dependence is explained in a comprehensive model, based on two magnetic sublattices and taking into account magnetic field-induced modifications of the domain structure. Our results show that the SMR effect allows to readout the spin configuration and to investigate magnetoelastic effects in antiferromagnetic multi-domain materials. We demonstrate that the SMR amplitude scales with the sum of the absolute sublattice magnetizations in ferrimagnetic and antiferromagnetic materials. In alpha-Fe2O3/Pt bilayers, we find an unexpectedly large SMR amplitude of 2.5E-3, twice as high as for prototype Y3Fe5O12/Pt bilayers, making the system particularly interesting for room-temperature antiferromagnetic spintronic applications.
Comments2 pages, 2 figures
Journal ref2023 IEEE International Magnetic Conference - Short Papers INTERMAG Short Papers, 1-2 (2023)
DOI：10.1109/INTERMAGShortPapers58606.2023.10228841
