Exploring the Nuclear Magnetic Resonance (NMR) technique as tool for modern materials research

现代材料研究的主要挑战之一是理解和控制结构-性质-关系，以便定制功能(磁性)材料的特定性质。这一事实需要对结构和(磁)性质进行彻底的分析，特别是如果为了控制性质而改变给定材料的结构，例如通过退火、离子辐照、成分替代或通过缩小尺度来产生纳米级物体，则尤其需要解决这一问题。本项目旨在探索作为复杂方法的核磁共振的能力，以在局部范围内研究选定的功能磁性材料的结构、磁和电子结构的改变，并进一步推进核磁共振方法。在本项目期间，我们将探索将核磁共振作为监测材料变化的工具；我们将使用四个选定的参数来修改结构和性能，以挑战核磁共振技术：(I)我们将应用离子束辐照来改变化学顺序，并作为回应，显示出高自旋极化(Co2MnSi)、结构与磁性(Fe60Al40)和磁热性质(Fe-Rh)之间的强烈相互作用的不同功能金属间材料的磁性。离子辐照的影响是局部的，很难用X射线衍射仪来研究，我们将探索在什么程度上核磁共振能够解决辐照后的结构变化(目标1)，(Ii)我们将研究退火对MNN薄膜堆栈结构性质的影响。在这里，我们结合了核磁共振的三个进展，即我们将研究MNN和相邻的Co-Fe层的(局域)结构，我们将通过射频功率相关性来研究MNN和Co-Fe层的局域磁性，我们将揭示MNN和Co-Fe之间的界面(目标2)，(Iii)我们将研究Co2MnAlxSi1-x上取代系列中性质的演变，特别是半金属基态，揭示是否存在宿主和替代原子的统计分布，我们将了解额外的无序是否起作用，我们将测量替代后电子结构的变化(目标3)。(4)我们将把磁性金属间化合物材料缩小到纳米尺度，并探索核磁共振的能力和极限，以研究它们的性质，以响应它们的缩小尺寸(目标4)。核磁共振(核磁共振)是一种基于实验室的通用和灵敏的方法，可以遇到如上所述的详细结构、电子和磁性变化的研究问题。我们期待着挑战核磁共振技术来研究与现代材料研究相关的功能磁性材料。

One of the major challenges in modern materials research is the understanding and control of structure-property-relationships in order to tailor specific properties of functional (magnetic) materials. This fact requires a thorough analysis of structure and in response of the (magnetic) properties, and is, in particular, to be addressed if the structure of a given material is modified with the aim to control the properties, e.g. by annealing, ion irradiation, substitution of constituents or by downscaling to yield nanoscale objects.This project aims to explore the power of NMR as sophisticated method to study structural, magnetic and electronic structure modifications of selected functional magnetic materials on a local scale and to further advance the NMR method. During this project we will explore NMR as tool to monitor changes in the material; we will use four selected parameters to modify structure and properties to challenge the NMR technique: (i) we will apply ion beam irradiation to alter chemical order and in response the magnetic properties of different functional intermetallic materials showing high spin polarization (Co2MnSi), a strong interaction between structure and magnetic properties (Fe60Al40) and magnetocaloric properties (Fe-Rh). The impact of ion irradiation is local and difficult to be studied by e.g. XRD, we will explore to which extend NMR will be able to resolve the structural modifications upon irradiation (aim 1), (ii) we will study the impact of annealing on the structural properties of MnN film stacks. Here, we combine three advances of NMR, namely, we will study the (local) structure of both MnN and the adjacent Co-Fe layer, we will investigate the local magnetic properties by rf power dependencies and we will shed light on the interface between MnN and Co-Fe (aim 2), (iii) we will investigate the evolution of properties and in particular the half-metallic ground state in a substitution series on the of Co2MnAlxSi1-x, revealing whether there is a statistical distribution of host and substitution atoms, we will learn whether additional disorder plays a role and we will measure the changes in the electronic structure upon substitution (aim 3). (iv) We will downscale magnetic intermetallic materials to the nanoscale and explore the power and limits of NMR to study their properties in response to their downsizing (aim 4).Nuclear magnetic resonance (NMR) is a versatile and sensitive lab-based method to encounter the problem of investigating detailed structural, electronic and magnetic property changes as outlined above. We expected to challenge the NMR technique to study functional magnetic materials relevant for modern materials research.