Gargiani P, Cuadrado R, Vasili H B, Pruneda M, Valvidares M
ALBA Synchrotron Light Source, Cerdanyola del Valles, E-08290, Barcelona, Spain.
Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and The Barcelona Institute of Science and Technology, Campus UAB, Bellaterra, 08193, Barcelona, Spain.
Nat Commun. 2017 Sep 26;8(1):699. doi: 10.1038/s41467-017-00825-9.
Graphene-spaced magnetic systems with antiferromagnetic exchange-coupling offer exciting opportunities for emerging technologies. Unfortunately, the in-plane graphene-mediated exchange-coupling found so far is not appropriate for realistic exploitation, due to being weak, being of complex nature, or requiring low temperatures. Here we establish that ultra-thin Fe/graphene/Co films grown on Ir(111) exhibit robust perpendicular antiferromagnetic exchange-coupling, and gather a collection of magnetic properties well-suited for applications. Remarkably, the observed exchange coupling is thermally stable above room temperature, strong but field controllable, and occurs in perpendicular orientation with opposite remanent layer magnetizations. Atomistic first-principles simulations provide further ground for the feasibility of graphene-spaced antiferromagnetic coupled structures, confirming graphene's direct role in sustaining antiferromagnetic superexchange-coupling between the magnetic films. These results provide a path for the realization of graphene-based perpendicular synthetic antiferromagnetic systems, which seem exciting for fundamental nanoscience or potential use in spintronic devices.Antiferromagnetic spintronics may pave the way to innovative information storage devices with perpendicular coupling, however experimental demonstrations are still sparse. Here, the authors demonstrate a graphene-mediated perpendicular antiferromagnetic coupling between Fe and Co layers in a Fe/graphene/Co sandwich structure.
具有反铁磁交换耦合的石墨烯间隔磁系统为新兴技术提供了令人兴奋的机遇。不幸的是，由于强度较弱、性质复杂或需要低温，迄今为止发现的面内石墨烯介导的交换耦合并不适合实际应用。在此，我们证实生长在Ir(111)上的超薄Fe/石墨烯/Co薄膜表现出强大的垂直反铁磁交换耦合，并具有一系列适合应用的磁性能。值得注意的是，观察到的交换耦合在室温以上具有热稳定性，强度大但可通过磁场控制，并且发生在垂直方向上，剩余层磁化方向相反。原子第一性原理模拟为石墨烯间隔反铁磁耦合结构的可行性提供了进一步依据，证实了石墨烯在维持磁膜之间反铁磁超交换耦合中的直接作用。这些结果为实现基于石墨烯的垂直合成反铁磁系统提供了一条途径，这对于基础纳米科学或在自旋电子器件中的潜在应用似乎令人兴奋。反铁磁自旋电子学可能为具有垂直耦合的创新信息存储设备铺平道路，然而实验证明仍然很少。在此，作者展示了在Fe/石墨烯/Co三明治结构中Fe和Co层之间的石墨烯介导的垂直反铁磁耦合。
