Exploring new functionalities of magnetic materials utilizing nanoplasmonics and multiferroics

利用纳米等离子体和多铁性探索磁性材料的新功能

• 批准号: RGPIN-2018-03765
• 负责人: Choi, ByoungChul
• 金额: $ 2.04万
• 依托单位: University of Victoria
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2018
• 资助国家: 加拿大
• 起止时间: 2018-01-01 至 2019-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=647592
• 关键词: Exploring; new; functionalities; magnetic; materials

The purpose of this proposal is to explore new functionalities of magnetic materials utilizing nanoplasmonics and multiferroics. In particular, we are interested in developing new ways to control magnetism optically or electrically.*** In the first part of the research, we will investigate the interaction between light and magnetism, which is of utmost importance in terms of fundamental science and technological applications. A specific goal is the ultrafast light control of magnetism. The strength of the interaction of light with a magnetic medium, however, is very weak, and this weak interaction has been the main challenge in optically probing or controlling magnetism. In order to overcome this drawback, we will exploit magneto-plasmonics, which combines magnetic and plasmonic functionalities. In our previous studies, we observed that the incorporation of noble-metal nanoparticles in ferromagnetic films significantly enhances magneto-optical (MO) effect. We will conduct systematic studies on the influence of plasmon resonance on MO effect, and develop a better understanding of the underlying mechanism of the enhanced MO activities. We will also study the ultrafast magnetism triggered by optically excited high energy electrons. The questions to be answered are: can we enhance the optical generation of hot electrons via localized surface plasmon resonance? If so, how effectively can we manipulate the hot-electron induced ultrafast magnetic process? Another project is to generate large wavenumber spin waves using ultrafast optical excitation. It is known that the spin wavenumber is determined by the spatial intensity distribution of the pumping light. We will be able to reduce the pump spot size to the nanoscale by using near-field optics. Higher spin wavenumbers can also be generated by using the localized surface plasmon resonance, in which the spatial intensity distribution is determined by the geometries of the nanoparticles.*** The second part of the research is to explore the opportunity of electric-field control of magnetism utilizing magnetoelectric multiferroics, which enables the coupling between magnetic and ferroelectric orders. However, room temperature multiferroics are very rare, with BiFeO3 (BFO) being an exception. Its drawback is that it has a very weak magnetic moment. Recently, it was found that a double perovskite material Bi2FeCrO6 (BFCO) has ferroelectricity similar to BFO with the added benefit of a strong magnetic moment. Our main goal is to answer the question whether BFCO can provide a new avenue for electric-field switching of magnetism. We will also investigate the electric-field triggered magnetization dynamics in gated BFCO thin films. Considering that the electric-field control of magnetism enabled by multiferroics has the potential to revolutionize today's electronics technology, the outcome of the proposed research will be significant.

该提案的目的是探索利用纳米质谱和多表面的磁性材料的新功能。特别是，我们有兴趣开发新的方法来控制磁性。申请。一个具体的目标是对磁性的超快光控制。但是，光与磁介质的相互作用的强度非常弱，这种弱相互作用一直是光学探测或控制磁性的主要挑战。为了克服这一缺点，我们将利用磁性和等离子功能的磁性播种。在我们先前的研究中，我们观察到在铁磁膜中掺入贵族金属纳米颗粒会显着增强磁光（MO）效应。我们将对等离子体共振对MO效应的影响进行系统研究，并更好地了解增强的MO活动的潜在机制。我们还将研究由光学激发高能电子触发的超快速磁性。要回答的问题是：我们可以通过局部表面等离子体共振增强热电子的光学生成吗？如果是这样，我们如何有效地操纵热电子诱导的超快磁过程？另一个项目是使用超快光激发产生大型波数旋转波。众所周知，自旋波数是由抽水灯的空间强度分布确定的。我们将能够使用近场光学元件将泵的斑点尺寸降低到纳米级。也可以通过使用局部表面等离子体共振来产生较高的自旋波数，其中空间强度分布取决于纳米颗粒的几何形状。***该研究的第二部分是探索探索电场控制的机会利用磁电多铁素化学的磁性，可以在磁性和铁电阶之间进行耦合。但是，室温多表色非常罕见，而Bifeo3（BFO）是例外。它的缺点是它具有非常弱的磁矩。最近，发现双钙钛矿材料bi2fecro6（BFCO）具有类似于BFO的铁电性，具有强磁矩的额外好处。我们的主要目标是回答一个问题，BFCO是否可以为磁性电场转换提供新的途径。我们还将研究封闭的BFCO薄膜中电场触发的磁化动力学。考虑到由多铁染料实现的磁性电场控制有可能彻底改变当今的电子技术，因此拟议的研究的结果将是重要的。