Domain structures and dynamics in Ferromagnetic shape memory materials: Theory and Experiment - Dynamic metallographic and magneto-optical polarization microscopy of MSMA systems

该项目是一个旨在理解磁性形状记忆材料中磁性和结构重定向过程机制的联合合作项目的一部分。该研究的目的是深入了解铁磁形状记忆合金（MSMA）的磁力学行为。我们研究这些样品的主要工具是光学偏振显微镜，它可以检测不同双胞胎变体的偏振对比。我们也将探讨磁畴结构，使用磁光指示膜技术。能够同时研究磁性和机械微观结构，使我们能够研究两种不同微观结构的相互依赖和相互影响。这些研究将包括在缓慢变化的磁场中的准静态过程，以及在时间分辨率为几微秒的脉冲磁场中更快地逆转。调查还将包括研究不同温度下的样品，以确定对孪晶界运动和迁移率起作用的影响。这些结果将为理论小组提供有用的输入，以测试和完善他们在MSMA样品中的磁力学模型。此外，该项目广泛受益于与参与spp1239的其他准备和实验组的强互动。

This project is part of a joint collaboration aiming at the understanding of the mechanisms of magnetic and structural reorientation processes in magnetic shape memory materials.The aim of the research is to obtain a deep insight into the magneto-mechanical behavior of ferromagnetic shape memory alloys (MSMA). Our main tool to investigate those samples is optical polarization microscopy, which can detect the polarization contrast of different twin variants. We will also explore the magnetic domain structure, using a magneto-optical indicator film technique. Being able to study both, the magnetic and mechanical microstructure, enables us to investigate interdependencies and mutual influences of the two different microstructures.The studies will include quasi-static processes in slowly changing magnetic fields and faster reversal using pulsed magnetic fields with temporal resolutions of the order of a few microseconds. The investigations will also incorporate studying the samples with varying temperatures in order to determine the contributing effects, which act on twin boundary motion and mobility.The results will provide useful input to the theory groups in the package to test and refine their models on the magneto-mechanics in MSMA samples.Moreover, the project extensively profits from the strong interaction with other preparational and experimental groups participating in the SPP 1239.