XPEEM of anisotropic dipolar coupling in periodic nanomagnet arrays.

自组装和图案化的磁性纳米结构是当前非常感兴趣的主题，由于它们在未来纳米技术中的巨大潜力。高密度磁记录是一个有望受益于使用图案化介质的领域，其潜在的存储密度比磁盘驱动器中当前可用的存储密度高1000倍。除了技术上的好处，图案化的纳米磁性阵列还提供了一个很好的机会来研究模型系统中的基本磁性和纳米磁性。因此，它们具有优于非图案化薄膜材料和块体系统的天然优势。在这里，我们建议进行研究的NiFe图案阵列的纳米磁性与X射线光发射电子显微镜。利用美国伯克利实验室先进光源（ALS）的最先进的设备，我们想对纳米级磁点中的磁畴结构进行观察实验。最近已经用宏观技术（诸如MOKE）观察到，图案中的元件的特定几何配置（即，正方形或六边形）可以导致与图案的物理结构各向异性相关的元件之间的磁相互作用。因此，作为磁记录中的基本属性的磁化反转可以受到图案的对称性的影响。磁畴结构的直接观察，可以用XPEEM非侵入性地完成，可以直接证明磁化如何受到局部磁场的影响，以及相邻磁矩之间的相互作用及其对称性是否在再磁化过程中起着至关重要的作用。

Self-assembled and patterned magnetic nanostructures are currently the subject of much interest due to their enormous potential in future nanotechnology. High density magnetic recording is one area which promises to benefit from a move towards the use of patterned media, with potential storage densities up to 1000 times higher than currently available in magnetic disk drives. As well as the technological benefit patterned nanomagnetic arrays offer a great opportunity to study aspects of fundamental and nanoscopic magnetism in model systems. As such they possess natural advantages over non-patterned thin film materials and bulk systems. Here we propose to carry out studies of nanomagnetic properties of patterned arrays of NiFe with X-ray Photo Emmission Electron Microscope. Using the state-of the art facilities available at the Advanced Light Sourse (ALS), Berkeley laboratories, US, we would like to perform experiments on the observation of the magnetic domain structure in the nanoscopic magnetic dots. It has been recently observed with macroscopic techniques, such as MOKE, that a specific geometric configuration of elements in a pattern (i.e. square or hexagonal) may lead to magnetic interactions between the elements anisotropically correlated with the physical structure of the pattern. As a result, magnetisation reversal, which is the fundamental property in magnetic recording, can be affected by the symmetry of the pattern. A direct observation of the magnetic domain structure, which can be done non-invasively with XPEEM, can directly demonstrate how the magnetisation is affected by the local magnetic field and whether the interactions between the neighboring moments and their symmetry play a crucial role in the remagnetisation process.