Designer 3D Magnetic Mesostructures

设计师 3D 磁性细观结构

• 批准号: EP/E039944/1
• 负责人: Simon Bending
• 金额: $ 59.45万
• 依托单位: University of Bath
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2007
• 资助国家: 英国
• 起止时间: 2007 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=EP%2FE039944%2F1
• 关键词: Designer; 3D; Magnetic; Mesostructures

In a remarkable recent paper Xiao et al. at Argonne National Laboratories demonstrated that 'architecture-tuneable' Pb mesostructures (samples whose dimensions lie between microscopic 'atomic' scales and macroscopic 'bulk' scales at which the specific geometry no longer plays a role for physical properties) can be grown by electrodeposition from lead salt solutions onto graphite substrates. Simply varying the electrode potentials allows an extraordinary variety of different sample morphologies to be realised, ranging from regular polyhedra and nanowires to multipods and 'snowflakes'. These structures are truly three-dimensional (3D) superconducting mesocrystals with few bulk defects and perfectly smooth faceted faces, whose magnetic properties are dominated by their size and shape. The same deposition method should be readily extendable to many ferromagnetic metals and alloys. For the first time it is now possible to controllably fabricate regular faceted 3D mesoscrystals without the disorder and rough surfaces/edges characteristic of lithographically-patterned thin film structures. Crucially, the dimensions of these 3D mesostructures are comparable with the relevant characteristic lengthscales found in ferromagnetism and superconductivity (e.g. ferromagnetic domain size and/or domain wall width or superconducting coherence length and/or magnetic field penetration depth) in contrast to widely studied nanoscale particles/clusters and nanowires. Competition between different processes as a function of the size and shape of these 3D structures should lead to rich new physical phenomena with strong potential for exploitation. In collaboration with the Argonne group we have shown that surface/shape effects can completely dominate the magnetisation of these materials, opening up the possibility of 'designing' crystals with desirable, exploitable properties. We propose to considerably extend the scope of this work within a collaboration between well established groups in electrochemistry and nanoscale physics at the University of Bath and theoreticians in Southampton and Antwerp. We plan to grow and investigate both superconducting and ferromagnetic mesocrystals with a wide range of morphologies, as well as hybrid ferromagnetic-superconductor core-shell structures and continuous hybrid networks. The most promising materials produced will be systematically characterised using Hall nanomagnetometry and/or magnetoresistance measurements. Experimental results will be interpreted by comparison with tailor-made state-of-the-art 3D micromagnetic simulations and/or solutions of the 3D Ginzburg-Landau equation. Opportunities for exploitation of these novel magnetic materials will also be identified and explored.

在最近的一篇非凡的论文中，Xiao等人。在Argonne国家实验室在Argonne国家实验室表明，“构造” PB介质（尺寸的样品位于显微镜“原子”量表和宏观的“大量”量表之间，特定几何不再在该尺度上起作用，可以通过从铅盐溶液中进行电溶液来生长物理特性的作用）。只需改变电极电位，就可以实现各种不同的样品形态，从常规的多面体和纳米线到多型动物和“雪花”。这些结构是真正的三维（3D）超导晶体，具有少量缺陷和完全光滑的面部面孔，其磁性特性由它们的大小和形状主导。相同的沉积方法应容易扩展到许多铁磁金属和合金。现在，第一次可以控制地制造常规的刻面3D介质晶体，而无需混乱和粗糙的表面/边缘/边缘的光刻图案薄膜结构的特征。至关重要的是，这些3D介质结构的尺寸与在铁磁和超导性中发现的相关特征长度尺寸（例如，铁磁性域的大小和/或域壁宽或超导宽度或超导性相干性长度和/或磁场渗透深度）相比，与广泛的Nananscale/nan scripers/Closters相比，相比之下。不同过程之间的竞争是这些3D结构的大小和形状的函数，应带来丰富的新物理现象，具有强大的剥削潜力。与Argonne组合作，我们表明表面/形状效应可以完全主导着这些材料的磁化，从而打开了具有理想，可剥削性能的“设计”晶体的可能性。我们建议在Bath大学的电化学和纳米级物理学与纳米级物理学的合作与南安普敦和安特卫普的理论家之间的合作范围内大大扩展这项工作的范围。我们计划成长和研究具有广泛形态的超导和铁磁中晶，以及混合铁磁 - 磁性磁导体核心壳结构和连续的混合网络。生产的最有希望的材料将使用HALL纳米磁测量法和/或磁势测量系统地进行系统表征。实验结果将通过与3D Ginzburg-Landau方程的量身定制的3D微型模拟和/或解决方案进行比较来解释。还将确定并探索开发这些新型磁性材料的机会。