Vibrating Sample Magnetometer

申请小组的主要专长是具有定制磁性能的功能纳米材料领域。本文研究了用于磁性微物体操纵和远程控制的平面层系统的人工畴结构和相关的微尺度磁杂散场景观。同样，研究了磁性功能化3D物体的磁性，例如磁性Janus粒子和管状结构。为此，深入了解磁性薄膜各向异性和交换相互作用之间的相互作用是必不可少的。在这里，一个核心问题是，当与外部磁场结合时，如何通过keV氦离子轰击来调整磁各向异性。重点是通过各自的理论建模研究热激活过程及其对材料系统磁化曲线特性的影响。对样品的磁化曲线进行定量表征是目前正在运行和计划中的项目的重要组成部分，该曲线对埋藏层、曲面和颗粒物体具有高灵敏度。因此，需要一种能够表征外磁场方向相对于样品各向异性轴、测量时间和温度系统变化下的磁化反转的仪器。要对平面、曲面和颗粒体系中的薄磁层进行研究，必须对样品的磁矩进行高灵敏度定量。高性能振动样品磁强计完全可以满足上述要求。由于测量过程集成在整个样品上，因此该技术对埋藏层也很敏感，因此是Kerr磁力计和Kerr显微镜的补充。由于该集团自制的振动样品磁力计组件的技术过时，其灵敏度太低，无法进行充分的样品表征。此外，也不可能进行温度控制和获得与角度相关的磁化曲线研究。因此，这种设置不适合进行计划中的调查。因此，所要求的新设备是计划研究所必需的。

The applicant group’s main expertise is in the field of functional nanomaterials with tailored magnetic properties. Here, artificial domain structures and associated microscale magnetic stray field landscapes are investigated for planar layer systems, which are used for manipulation and remote control of magnetic microobjects. Likewise, magnetic properties of magnetically functionalized 3D objects are explored, e.g., magnetic Janus particles and tubular architectures. For this purpose, a profound understanding of the interplay between anisotropies and exchange interaction in magnetic thin films is essential. Here, a central question is how magnetic anisotropies can be tailored by keV helium ion bombardment when combined with external magnetic fields. The focus is on investigating thermally activated processes with respective theoretical modeling and their impact on characteristics of the material systems’ magnetization curves.An essential part for carrying out the currently running and planned projects is a quantitative characterization of the samples’ magnetization curves with high sensitivity to buried layers, curved surfaces and particulate objects. Therefore, an instrument is required, which is capable to characterize the magnetization reversal under systematic variation of the external magnetic field’s direction with respect to the samples’ anisotropy axes, the measurement time and temperature. As investigations on thin magnetic layers in planar, curved and particulate systems are required, an essential condition is to quantify the samples’ magnetic moment with high sensitivity. The described requirements can be entirely fulfilled by a high-performance vibrating sample magnetometer. Because the measurement procedure integrates over the whole sample, this technique is also sensitive to buried layers and is therefore complementary to the Kerr magnetometers and Kerr microscope available in the group. Due to the outdated technology of the group’s home-built vibrating sample magnetometer’s components, its sensitivity is orders of magnitude too low for an adequate sample characterization. In addition, there is no possibility for temperature control and for acquiring angular dependent magnetization curve studies. Therefore, this set-up is not suitable for carrying out the planned investigations. Consequently, the requested new device is necessary for the planned research.