Department of Physics and Astronomy, Uppsala University, Box 516, Uppsala 751 20, Sweden.
Science Institute, University of Iceland, Dunhaga 3, Reykjavik IS-107, Iceland.
Nat Commun. 2016 Jun 13;7:ncomms11931. doi: 10.1038/ncomms11931.
Low-dimensional magnetic heterostructures are a key element of spintronics, where magnetic interactions between different materials often define the functionality of devices. Although some interlayer exchange coupling mechanisms are by now well established, the possibility of direct exchange coupling via proximity-induced magnetization through non-magnetic layers is typically ignored due to the presumed short range of such proximity effects. Here we show that magnetic order can be induced throughout a 40-nm-thick amorphous paramagnetic layer through proximity to ferromagnets, mediating both exchange-spring magnet behaviour and exchange bias. Furthermore, Monte Carlo simulations show that nearest-neighbour magnetic interactions fall short in describing the observed effects and long-range magnetic interactions are needed to capture the extent of the induced magnetization. The results highlight the importance of considering the range of interactions in low-dimensional heterostructures and how magnetic proximity effects can be used to obtain new functionality.
低维磁性异质结构是自旋电子学的关键元素，不同材料之间的磁相互作用通常决定了器件的功能。尽管现在已经确定了一些层间交换耦合机制，但由于假定这种近邻效应的范围很短，通常忽略了通过非磁性层的近邻感应磁化直接进行交换耦合的可能性。在这里，我们表明通过与铁磁体的近邻，整个 40nm 厚的非晶态顺磁层中可以诱导出磁有序，从而介导交换弹簧磁行为和交换偏置。此外，蒙特卡罗模拟表明，最近邻磁相互作用不足以描述观察到的效应，需要长程磁相互作用来捕获感应磁化的程度。这些结果强调了在低维异质结构中考虑相互作用范围的重要性，以及如何利用磁近邻效应获得新的功能。
