Controlling cooperative phenomena in nanomagnetic systems - New physics and its application

控制纳米磁系统中的协同现象——新物理及其应用

• 批准号: 311888-2013
• 负责人: vanLierop, Johan
• 金额: $ 2.33万
• 依托单位: University of Manitoba
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2016
• 资助国家: 加拿大
• 起止时间: 2016-01-01 至 2017-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=595028
• 关键词: Controlling; cooperative; phenomena; nanomagnetic; systems

This research program will make possible the next generation of devices and applications based on controlled magnetism at the nanoscale by following three complementary themes. Firstly, my group will continue to pioneer discoveries into the physics of cooperative phenomena driving magnetism in macro-sized crystals made of nanoparticles. By using nature's inherent mechanisms to drive three-dimensional self-assembly of nanoparticles, the well known atom's magnetism is enhanced by ten-thousand-fold in nanoparticles. Our work investigates the unique properties of magnetic nanoparticles forming different crystal structure environments. Magnetic ordering from interactions between atoms in a crystal is a well understood phenomenon. By contrast, amongst nanoparticles in a structurally ordered configuration, the magnetism is largely unexplored. Secondly, my group will research how to recapture the magnetism lost due to finite size and surface effects - especially prevalent amongst iron-oxide and ferrite-based nanoparticles that are the basis of a large amount of applied physics. Surface magnetism is disordered and this frustrates a nanoparticle from achieving its maximal magnetization. We are discovering ways of control via tuning quantum confinement effects and identifying the physics of the cooperative phenomena that surface and core atomic moments undergo. Short term benefits include using nanoparticles as vehicles optimized for drug delivery, MRI magnetic contrast agents and improved magnetic hyperthermia. Thirdly, my group is investigating ferromagnetism and antiferromagnetism (the two fundamental forms of cooperative phenomena at the atomic-scale) and how they interact at the limit of today's technology and beyond. Proximity effects and parts with compositional and structural constrictions dominate the physics of the magnetism at the nanoscale. By considering ways to control magnetic properties like anisotropy and domain configuration, we will acquire a better understanding of relevant devices such as hard-drive read/write heads and spin-valves used in 'spintronic'-based devices.

该研究计划将通过遵循三个互补主题，使下一代基于纳米级受控磁的设备和应用程序成为可能。首先，我的小组将继续开拓性的发现，使其在纳米颗粒制成的宏观晶体中驱动磁性的合作现象的物理学。通过使用自然的固有机制来驱动纳米颗粒的三维自组装，在纳米颗粒中，众所周知的原子的磁性增强了。我们的工作研究了形成不同晶体结构环境的磁性纳米颗粒的独特特性。晶体中原子之间相互作用的磁顺序是一种充分了解的现象。相比之下，在结构有序结构中的纳米颗粒中，磁性在很大程度上没有探索。其次，我的小组将研究如何重新捕获由于有限的大小和表面影响而损失的磁性 - 尤其是在铁氧化物和铁素铁素体的纳米颗粒中普遍存在，这些纳米颗粒是大量应用物理学的基础。表面磁性是无序的，这使纳米颗粒无法获得最大磁化。我们正在通过调整量子限制效应来发现控制方法，并确定表面和核心原子矩经历的合作现象的物理。短期益处包括使用纳米颗粒作为用于药物输送的车辆，MRI磁对比剂和改善的磁性高温。第三，我的小组正在调查铁磁主义和反铁磁性（原子级合作现象的两种基本形式），以及它们如何以当今技术及其他地区的极限相互作用。近端效应和组成和结构收缩的部分主导着纳米级磁性的物理。通过考虑控制磁性特性（例如各向异性和域配置）的方法，我们将更好地理解相关设备，例如基于“ Pertronic”的设备中使用的硬驱动读/写头和旋转阀门。