Cantilever (torque) detected multifrequency electron spin resonance spectroscopy of halfmetallic compounds and endohedral metallofullerenes

悬臂（扭矩）检测半金属化合物和内嵌金属富勒烯的多频电子自旋共振光谱

• 批准号: 321732198
• 负责人: Dr. Alexey Alfonsov, Ph.D.
• 金额: --
• 依托单位: Leibniz-Institut für Festkörper- und Werkstoffforschung Dresden (IFW) e.V.
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2016
• 资助国家: 德国
• 起止时间: 2015-12-31 至 2020-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/321732198?language=en
• 关键词: Cantilever; torque; detected; multifrequency; electron

In this project we propose to build a highly sensitive multifrequency cantilever-based (torque-detected) electron spin resonance (ESR) spectrometer, and to use it for studies of magnetic anisotropic properties of halfmetallic ferromagnets and endohedral metallofullerenes. Magnetic anisotropy always goes side by side with other fundamental properties, such as electronic correlations in transition metal oxides, in the metallic alloys, or in all kinds of molecular magnets (MM), including endohedral metallofullerenes (EMF). Therefore the study of the magnetic anisotropy provides direct insights into the intrinsic properties of different materials. This can further lead to the observation of new phenomena, or to the improvement of the known properties, so that the material can find technological applications. In the case of halfmetallic ferromagnets magnetic anisotropy as well as such dynamic property as a damping are responsible for the stability of the magnetization and for the ability to switch the magnetic state. Magnetic anisotropy in EMFs, which exhibit single molecular magnet behavior, could yield long living quantum states with zero-field relaxation times reaching several hours. For these materials the size of the sample plays a crucial role: metallic alloys promising for spintronics application has to be made as a thin, nm-size, films, in order to fulfill the requirements for building a device; molecular magnets, such as EMFs, where each molecule has a nanometer size, are especially interesting when deposited on the substrate as single layer. In order to have full access to the magnetic properties it is essential to measure ESR on above mentioned compounds at various frequencies, magnetic fields and at different angles between the sample and the applied magnetic field. This is not always possible in the standard ESR setups, due to a lack of sensitivity, or due to the restriction in frequency, strength and orientation of magnetic field. Cantilevers have an extremely high sensitivity, which is almost independent of the microwave frequency and magnetic field, and it is relatively easy to align them. This makes us confident that the constructed cantilever detected ESR setup will enable to explore static and dynamic magnetic anisotropic properties of halfmetallic ferromagnets and endohedral metallofullerenes.

在这个项目中，我们建议建立高度敏感的基于悬臂（扭矩检测）电子自旋共振（ESR）光谱仪，并将其用于研究半金属铁磁铁和内膜金属金属氟烯烯的磁各向异性特性。磁各向异性始终与其他基本特性并肩作用，例如过渡金属氧化物，金属合金中的电子相关性，或在各种分子磁体（MM）中，包括内he骨金属氟甲烯（EMF）。因此，对磁各向异性的研究提供了对不同材料的内在特性的直接见解。这可以进一步导致观察新现象或改善已知特性，从而可以找到技术应用。在半金属的铁磁体的情况下，磁各向异性以及阻尼的动态特性负责磁化的稳定性和切换磁性状态的能力。 EMF中表现出单分子磁铁行为的磁各向异性可以产生长期活的量子状态，而零场松弛时间达到了几个小时。对于这些材料，样品的大小起着至关重要的作用：为了满足构建设备的要求，必须将其用于Spintronics应用的金属合金构成薄，NM大小的薄膜。分子磁体（例如EMFS），每个分子具有纳米大小，当沉积在基板上作为单层时特别有趣。为了完全访问磁性特性，必须在各种频率，磁场和样品和施加的磁场之间的不同角度上测量上述化合物上的ESR。由于缺乏灵敏度或磁场的频率，强度和方向的限制，因此在标准ESR设置中并不总是可能。悬臂具有极高的灵敏度，几乎与微波频率和磁场无关，并且对齐它们相对容易。这使我们确信，构造的悬臂检测到的ESR设置将使半金属铁磁体和内膜金属氟烯烯的静态和动态磁各向异性特性探索。