Characterization of the micro- and nanostructure of magnetic shape memory materials by Transmission Electron Microscopy (TEM).

该项目应该揭开铁磁形状记忆合金(FSMA)真实结构的未知特征，特别是薄膜材料。为此，选择了透射式电子显微镜方法的组合方法，包括电子衍射、高分辨率成像和电子或X射线光谱技术的最新技术。由于材料性能的优化只能从对纳米结构、缺陷和不均匀性的精确知识中得出，因此特别强调用原子分辨率来研究结构和组成。对于FSMA来说，纳米级沉淀物的鉴定和化学分析特别重要，因为它们对材料的功能至关重要。此外，FSMA的结构是由结构和磁场构成的，需要用先进的成像技术进行分析，如高分辨率电子显微镜和洛伦茨显微镜。这些检查的范围从分析具有纳米级调制的复杂结构到原子在界面上的排列。应该分析化学取代和掺杂对真实结构的影响，从而揭示材料和器件的真实结构-性能关系。此外，基于加热效应的势能器件的化学或结构变化可以通过原位加热实验监测到接近原子分辨率。该项目的跨学科性质通过与SPP 1239选定的小组进行技能密集合作而得到强调，这些小组是FSMA功能的特征，并为透射电子显微镜分析提供材料。

The project should unravel unknown features of the real structure of ferromagnetic shape memory alloys (FSMA) with particular focus on thin film materials. For this purpose, a combined approach of transmission electron microscopy (TEM) methods is selected including state of the art techniques of electron diffraction, high resolution imaging and electron- or X-ray spectroscopy. Particular emphasis is on the investigation of structure and composition with atomic resolution since the optimization of material properties can only be derived from a precise knowledge about nanostructure, defects and inhomogeneities. For FSMA the identification and chemical analysis of nanoscale precipitates are of particular importance, since they are critical for the function of the material. Moreover, the structures of FSMA are built from structural and magnetic domains calling for analyses by advanced imaging techniques, like high resolution TEM and Lorentz microscopy, respectively. These examinations range from the analysis of complex structures with nanoscale modulations up to the arrangement of atoms at interfaces. The influence of chemical substitutions and doping on the real structure should be analyzed thus revealing real structure-property relations of materials and devices. Moreover, chemical or structural changes of potential devices based on heating effects can be monitored close to atomic resolution by in-situ heating experiments. The interdisciplinary nature of the project is emphasized by the skill-intensive cooperation with selected groups of SPP 1239 which characterize the function of FSMA and provide the materials for the TEM analyses.