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

新型磁性杂化材料的微观结构和磁性表征

• 批准号: 276390678
• 负责人: Professor Dr. Stefan Odenbach
• 金额: --
• 依托单位: Department of Mathematical Physics
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2015
• 资助国家: 德国
• 起止时间: 2014-12-31 至 2018-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/276390678?language=en
• 关键词: Micorstructural; magnetic; characterisation; new; kind

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 the research association a mixture of magnetically hard and soft particles in an elastomeric matrix is expected to provide a combination of active and passive magnetorheological properties. In this context, it will be 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 will be in focus of the working program. The microstructural investigations will use X-ray microtomography measurements allowing a three-dimensional evaluation of the particle distribution with single particle resolution. For this purpose tools for digital image analysis enabling an effective determination of the different particle species will have to be developed first. Afterwards the particle distribution and their change under influence of external stimuli like magnetic field and mechanical load will be analysed. The respective data will serve as well as an input as as a benchmark for the simulations undertaken by the theoretically working groups within the research association. Since the reorganisation of the microstructure is significantly determined by the magnetic interparticle interaction between the different particles, the second part of the subproject will focus on an experimental approach to the change of these interactions by changes of the composition of the magnetic hybrid material. Therefore First Order Reversal Curves (FORCs), i.e. partial hysteresis loops will be recorded. Preliminary investigations have shown that these data are sensitive for the composition of the magnetic hybrid materials and provide clear fingerprints of the internal magnetic interaction of the particles. A 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.

经典的磁性混合材料包含软磁或硬磁颗粒。因此，它们显示出主动磁流变效应或在硬磁颗粒磁化后表现出被动磁流变性质。在研究协会内，在弹性体基质中的硬磁和软磁颗粒的混合物预计将提供主动和被动磁流变性能的组合。 在这种情况下，它将是研究协会的中心目标，合成量身定制的磁性混合材料的传感器应用的基础上详细的微观理解的材料特性。在这里描述的子项目中，微观结构调查以及磁性粒子间相互作用的实验分析将是工作计划的重点。微观结构调查将使用X射线显微断层扫描测量，允许三维评估的颗粒分布与单颗粒分辨率。为此，必须首先开发能够有效确定不同颗粒种类的数字图像分析工具。然后分析颗粒分布及其在磁场和机械载荷等外部刺激影响下的变化。各自的数据将作为研究协会内理论工作组进行模拟的基准。由于微观结构的重组主要取决于不同颗粒之间的磁性颗粒间相互作用，因此该子项目的第二部分将侧重于通过改变磁性混合材料的组成来改变这些相互作用的实验方法。因此，将记录一阶阻尼曲线（FORC），即部分磁滞回线。初步研究表明，这些数据对磁性混合材料的组成敏感，并提供了颗粒内部磁相互作用的清晰指纹。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。总的来说，我们希望该项目将提供有关磁混合材料的微观结构变化和宏观性能之间关系的详细信息。 该信息将为预测某些材料特性提供基础，这可以通过材料组成的相应变化来实现。