Menéndez Enric, Liedke Maciej Oskar, Fassbender Jürgen, Gemming Thomas, Weber Anja, Heyderman Laura J, Rao K V, Deevi Seetharama C, Suriñach Santiago, Baró Maria Dolors, Sort Jordi, Nogués Josep
Departament de Física, Universitat Autònoma de Barcelona, Bellaterra, Spain.
Small. 2009 Feb;5(2):229-34. doi: 10.1002/smll.200800783.
Sub-100-nm magnetic dots embedded in a non-magnetic matrix are controllably generated by selective ion irradiation of paramagnetic Fe(60)Al(40) (atomic %) alloys, taking advantage of the disorder-induced magnetism in this material. The process is demonstrated by sequential focused ion beam irradiation and by in-parallel broad-beam ion irradiation through lithographed masks. Due to the low fluences used, this method results in practically no alteration of the surface roughness. The dots exhibit a range of magnetic properties depending on the size and shape of the structures, with the smallest dots (<100 nm) having square hysteresis loops with coercivities in excess of micro(0)H(C) = 50 mT. Importantly, the patterning can be fully removed by annealing. The combination of properties induced by the direct magnetic patterning is appealing for a wide range of applications, such as patterned media, magnetic separators, or sensors.
通过对顺磁性Fe(60)Al(40)（原子百分比）合金进行选择性离子辐照，利用该材料中无序诱导的磁性，可控地生成了嵌入非磁性基质中的亚100纳米磁性点。通过顺序聚焦离子束辐照以及通过光刻掩模进行的并行宽束离子辐照证明了该过程。由于使用的通量较低，该方法实际上不会改变表面粗糙度。这些点根据结构的尺寸和形状表现出一系列磁性特性，最小的点（<100纳米）具有方形磁滞回线，矫顽力超过μ(0)H(C)=50 mT。重要的是，通过退火可以完全去除图案。直接磁性图案化所诱导的特性组合对于广泛的应用具有吸引力，例如图案化介质、磁分离器或传感器。
