Micorstructural and magnetic characterisation of a new kind of magnetic hybrid materials

经典的磁杂化材料包含磁软或磁硬颗粒。因此，在磁性硬颗粒磁化后，它们表现出主动磁流变效应或被动磁流变特性。在这个由德国和俄罗斯项目组组成的研究协会中，我们将磁性硬颗粒和磁性软颗粒结合在弹性体基质中，以提供主动和被动磁流变特性的组合。在这种情况下，研究协会的中心目标是基于对材料特性的详细微观理解，为传感器应用合成定制的磁性混合材料。在这里描述的子项目中，微观结构研究以及磁性粒子间相互作用的实验分析是工作计划的重点。微观结构研究使用x射线显微断层扫描测量，允许对单粒子分辨率的粒子分布进行三维评估。在申请的项目阶段，我们将特别关注混合材料中小颗粒重组的评估，因为这些在材料的理论描述中起着重要作用。此外，在磁化过程中以及在机械载荷下的结构变化将通过显微断层扫描进行检查。各自的数据既可作为输入，也可作为研究协会内理论工作组进行模拟的基准。利用一阶反转曲线（FORCs）研究不同粒子间的磁性相互作用，以阐明粒子形状对与基体相互作用的影响，从而对杂化材料的结构重组和磁性行为的影响。对数据的详细解释需要对曲线有更深的理论理解，这将由理论工作组提供。总而言之，我们期望该项目将为磁性杂化材料的微观结构变化与宏观性能之间的关系提供详细的信息。这些信息将为预测某些材料特性提供基础，这些特性可以通过材料成分的各自变化来实现。

Classical magnetic hybrid materials contain either magnetically soft or magnetically hard particles. Thus, they show either an active magnetorheological effect or exhibit passive magnetorheological properties after magnetization of the magnetically hard particles. Within this research association of German and Russian project groups we combine magnetically hard and soft particles in an elastomeric matrix to provide a combination of active and passive magnetorheological properties. In this context, it is the central goal of the research association to synthesize tailored magnetic hybrid materials for sensor applications based on a detailed microscopic understanding of the material properties. Within the subproject described here, microstructural investigations as well as the experimental analysis of the magnetic interparticle interactions are in focus of the working program. The microstructural investigations use X-ray microtomography measurements allowing a three-dimensional evaluation of the particle distribution with single particle resolution. In the project phase applied for we will especially focus on the evaluation of reorganization of small particles in the hybrid material since these play an important role in the theoretical description of the material. Moreover structural changes as well during magnetization processes as under mechanical load will be examined by microtomography. The respective data serves as well as an input as as a benchmark for the simulations undertaken by the theoretically working groups within the research association. The investigations of magnetic interparticle interaction between the different particles using First Order Reversal Curves (FORCs) will be extended to clarify the influence of the particle shape on the interaction with the matrix and thus on structural reorganization and magnetic behaviour of the hybrid materials. The detailed interpretation of the data requires a deeper theoretical understanding of the curves, which will be provided by the theoretically working groups. In total, we expect that the project will provide detailed information about the relation between microstructural changes and macroscopic properties of the magnetic hybrid materials. This information will provide the basis for a prediction of certain material properties, which can be achieved by respective changes in composition of the material.