Magnetostrictive multilayers for magneto-electric sensors - layer structure and magnetic domains

该项目的重点是研究用于磁电2-2结构的新型磁致伸缩元件，重点是高灵敏磁场传感器在不同应用场景下的相关磁域工艺。在该项目中，将评估使用已知和新的磁性材料、材料组合以及制备优化磁电复合材料的替代方法的条件。为此，我们将研究具有高压磁系数的溅射磁性多层膜系统。除了有效的磁性材料参数对磁电响应的影响外，微结构和相关的磁畴结构的影响将是我们研究的中心，以实现对传感器的低检测下限。利用界面和静磁耦合现象来控制传感器的磁致伸缩相的行为，通过建模和空间分辨的磁表征方法，可以了解结构磁电多层膜的功能相关的磁过程。通过展示的巴克豪森噪声检测低频信号的已知限制将被消除。因此，例如结合交换偏置层，将系统地研究新的层系统。重点分析了不同工艺参数对器件磁畴结构的影响以及相应的传感器噪声。从简单模型结构中获得的基本知识将被转移到技术传感器结构中。此外，还将研究能够承受更高加工温度的创新材料组合。为了在获得高热稳定性的同时获得高的压磁系数，将探索FeCo/TiN多层膜结构。此外，还将研究具有最高灵敏度的传感器结构的替代方法。将开发高灵敏度磁电传感器的材料和物理基础。这一研究结果有望使2-2磁电复合材料的磁性能得到极大的改善。

The focus of the project is research on novel magnetostrictive components for magneto-electric 2-2 structures with a strong emphasis on the relevant magnetic domain processes for highly sensitive magnetic field sensors in different application scenarios. Within the project, the conditions for the use of known and also new magnetic materials, material combinations, and alternative approaches for the preparation of optimized magneto-electric composites are to be evaluated. For this purpose sputtered magnetic multilayer film systems with high piezomagnetic coefficients will be investigated. In addition to the influence of the effective magnetic material parameters on the magneto-electric response, the influences of the microstructure and the associated magnetic domain structure will be central to our studies in order to achieve a low limit of detection for the sensors. Interfacial and magnetostatic coupling phenomena are used to control the behavior of the magnetostrictive phase of the sensors.Through modeling and spatially resolved magnetic characterization methods, an understanding of the functional relevant magnetic processes of structured magneto-electric multilayers will be achieved. Known limitations in the detection of low frequency signals through exhibited Barkhausen noise will be eliminated. Therefore, e.g. in combination with exchange biased layers, novel layer systems will be systematically investigated. A special emphasis of the research lies in the analysis of the influences of different processing parameters on magnetic domain structure and the corresponding sensor noise exhibited by the devices. Fundamental knowledge obtained from simple model structures will be transferred to technical sensor structures. Moreover, innovative material combinations that can withstand higher processing temperatures will be investigated. In order to achieve high thermal stability together with high piezomagnetic coefficients FeCo/TiN multilayer structures will be explored. Moreover, alternative approaches for sensor structures with highest sensitivity will be investigated. The material and physical foundations for highly sensitive magneto-electric sensors will be developed. The results of the research are expected to lead to 2-2 magneto-electric composites with greatly improved magnetic properties.