We describe the microfabrication and magnetic behavior of composite/hybrid, two-dimensional, magnetostatically interacting, array of nanomagnets of Fe and exchange-biased bilayer Fe/IrMn heterostructures. Such an interacting array of nanomagnets, forming an artificial spin ice lattice, but with a hybrid structure has not been demonstrated before. These devices are fabricated of epitaxially grown Fe/IrMn thin films by a two-stage electron beam lithography process involving metal mask transfer and controlled ion milling. Following the epitaxial deposition of Fe/IrMn bilayer films, the first step involves electron beam lithography fabrication of nanomagnet arrays, followed by selective removal of exchange-bias by etching away IrMn layer at specific nanomagnet elements by ion milling. The technique described provides a way to apply a site-specific magnetic field at the nanometer length scale, utilizing the phenomenon of exchange-bias, as demonstrated here for an array with local fields applied at twice the period of the artificial spin ice lattice. This technology can also be readily extended to different spintronic devices requiring spatial distribution of exchange-bias fields.

中文翻译：

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具有周期性站点特定局部磁场的混合人工自旋冰阵列的制造

我们描述了复合/混合、二维、静磁相互作用、Fe 纳米磁铁阵列和交换偏置双层 Fe/IrMn 异质结构的微制造和磁性行为。这种相互作用的纳米磁体阵列形成人工自旋冰晶格，但具有混合结构，以前从未被证明过。这些器件由外延生长的 Fe/IrMn 薄膜通过涉及金属掩模转移和受控离子铣削的两阶段电子束光刻工艺制成。在外延沉积 Fe/IrMn 双层膜之后，第一步涉及纳米磁体阵列的电子束光刻制造，然后通过离子铣削在特定纳米磁体元素处蚀刻掉 IrMn 层来选择性去除交换偏置。所描述的技术提供了一种利用交换偏压现象在纳米长度尺度上应用特定于站点的磁场的方法，如此处针对以人工自旋冰晶格的两倍周期施加局部场的阵列所演示的那样。该技术还可以很容易地扩展到需要交换偏置场空间分布的不同自旋电子器件。