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

经典的磁性杂化材料含有软磁性或硬磁性颗粒。因此，它们要么表现出主动的磁流变效应，要么表现出磁硬颗粒磁化后的被动磁流变特性。在德国和俄罗斯项目组的这个研究协会内，我们将磁性硬颗粒和软颗粒组合在弹性基质中，以提供主动和被动磁流变性能的组合。在此背景下，该研究协会的中心目标是基于对材料性质的详细微观理解来合成用于传感器应用的定制磁性杂化材料。在这里描述的子项目中，微结构调查以及磁性粒子间相互作用的实验分析是工作方案的重点。微观结构研究使用X射线显微断层扫描测量，以单颗粒分辨率对颗粒分布进行三维评估。在申请的项目阶段，我们将特别关注杂化材料中小颗粒重组的评估，因为这些重组在材料的理论描述中起着重要的作用。此外，磁化过程中的结构变化以及在机械负载下的结构变化将通过显微断层扫描进行检查。各自的数据既是输入，也是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)研究不同颗粒之间的磁性相互作用，将有助于阐明颗粒形状对颗粒与基质相互作用的影响，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入的理论理解，这将由理论工作组提供。总而言之，我们预计该项目将提供关于磁性杂化材料微观结构变化与宏观性能之间关系的详细信息。这些信息将为某些材料性质的预测提供基础，这可以通过材料成分的相应变化来实现。

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.