Boix-Constant Carla, Mañas-Valero Samuel, Ruiz Alberto M, Rybakov Andrey, Konieczny Krzysztof Aleksander, Pillet Sébastien, Baldoví José J, Coronado Eugenio
Instituto de Ciencia Molecular (ICMol), Universitat de València, Catedrático José Beltrán 2, Paterna, 46980, Spain.
Université de Lorraine, CNRS, CRM2, Nancy, 54500, France.
Adv Mater. 2022 Oct;34(41):e2204940. doi: 10.1002/adma.202204940. Epub 2022 Sep 13.
2D magnetic materials offer unprecedented opportunities for fundamental and applied research in spintronics and magnonics. Beyond the pioneering studies on 2D CrI and Cr Ge Te , the field has expanded to 2D antiferromagnets exhibiting different spin anisotropies and textures. Of particular interest is the layered metamagnet CrSBr, a relatively air-stable semiconductor formed by antiferromagnetically-coupled ferromagnetic layers (T ∼150 K) that can be exfoliated down to the single-layer. It presents a complex magnetic behavior with a dynamic magnetic crossover, exhibiting a low-temperature hidden-order below T*∼40 K. Here, the magneto-transport properties of CrSBr vertical heterostructures in the 2D limit are inspected. The results demonstrate the marked low-dimensional character of the ferromagnetic monolayer, with short-range correlations above T and an Ising-type in-plane anisotropy, being the spins spontaneously aligned along the easy axis b below T . By applying moderate magnetic fields along a and c axes, a spin-reorientation occurs, leading to a magnetoresistance enhancement below T*. In multilayers, a spin-valve behavior is observed, with negative magnetoresistance strongly enhanced along the three directions below T*. These results show that CrSBr monolayer/bilayer provides an ideal platform for studying and controlling field-induced phenomena in two-dimensions, offering new insights regarding 2D magnets and their integration into vertical spintronic devices.
二维磁性材料为自旋电子学和磁子学的基础研究和应用研究提供了前所未有的机遇。除了对二维CrI₃和Cr₂Ge₂Te₆的开创性研究之外,该领域已扩展到表现出不同自旋各向异性和纹理的二维反铁磁体。特别令人感兴趣的是层状变磁体CrSBr,它是一种相对空气稳定的半导体,由反铁磁耦合的铁磁层(T ∼150 K)形成,可剥离至单层。它呈现出具有动态磁交叉的复杂磁行为,在T*∼40 K以下表现出低温隐藏序。在此,研究了二维极限下CrSBr垂直异质结构的磁输运性质。结果表明,铁磁单层具有明显的低维特性,在T以上具有短程关联,且具有面内各向异性的伊辛型,即自旋在T以下自发地沿易轴b排列。通过沿a轴和c轴施加适度磁场,会发生自旋重取向,导致在T以下磁电阻增强。在多层中,观察到自旋阀行为,在T以下沿三个方向负磁电阻强烈增强。这些结果表明,CrSBr单层/双层为研究和控制二维中的场致现象提供了理想平台,为二维磁体及其集成到垂直自旋电子器件中提供了新的见解。