High sensitivity SQUID magnetometer / AC susceptometer

高灵敏度SQUID磁力计/交流电感受器

• 批准号: 513830859
• 金额: --
• 依托单位: Universität Konstanz
• 依托单位国家: 德国
• 项目类别: Major Research Instrumentation
• 财政年份: 2022
• 资助国家: 德国
• 起止时间: 2021-12-31 至 无数据
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/513830859?language=en
• 关键词: sensitivity; SQUID; magnetometer; AC; susceptometer

Magnetic parameters such as the magnetic moment and the magnetic susceptibility play a fundamental role in the study and characterization of magnetic materials. With the SQUID magnetometer applied for here, the magnetic properties of thin magnetic films and magnetic heterostructures, ensembles of magnetic clusters or molecular magnets, as well as superconducting layers shall be investigated. An important part of the research work envisaged hereby aims at samples with ferrimagnetic or antiferromagnetic properties. These samples typically feature very small (net) magnetic moments, which can only be resolved with a highly sensitive, state-of-the-art magnetometer. More specifically, we want to use magnetometry measurements to quantitatively study the evolution of the magnetic moment as a function of magnetic field strength, magnetic field orientation and temperature. In addition to quantifying the saturation moment, the remanent moment and the magnetic coercive fields, such experiments also provide important insights into the magnetization reversal process and the magnetic anisotropy of the samples. Detailed knowledge about these magnetic properties is important for optimizing sample preparation processes, and for analyzing and interpreting measurement data acquired in other experiments. In addition, we want to use the possibility of recording magnetotransport and magnetization data simultaneously in one and the same sample in one and the same setup, in order to investigate the interplay between magnetic properties and magnetoresistive response, e.g. in the Verwey transition in magnetite, or in the anomalous or topological Hall effect in ferromagnets and antiferromagnets. Finally, in addition to magnetometry, we intend to use AC magnetic susceptibility measurements to quantify magnetic ordering temperatures and the existence and range of different magnetic phases. Since the imaginary part of the susceptibility is directly linked to magnetic dissipation, AC susceptibility measurements can also provide important information for the analysis of magnetic fluctuation phenomena, which currently are being studied by several groups within at the University of Konstanz.

诸如磁矩和磁化率之类的磁参数在磁性材料的研究和表征中起着基本作用。在此处使用鱿鱼磁力计，应研究薄磁性膜和磁异构结构的磁性，磁簇或分子磁体的集合以及超导层。在此设想的研究工作的重要部分是针对具有铁磁或抗铁磁特性的样品。这些样品通常具有很小的（净）磁矩，只能用高度敏感的，最先进的磁力计解决。更具体地说，我们希望使用磁化测量测量来定量研究磁矩的演变，这是磁场强度，磁场方向和温度的函数。除了量化饱和力矩，远期力矩和磁性强制场外，此类实验还为磁化反转过程和样品的磁各向异性提供了重要的见解。关于这些磁性特性的详细知识对于优化样品制备过程以及分析和解释其他实验中获得的测量数据很重要。此外，我们希望使用在一个和同一设置中同时在一个和同一样品中记录磁转运和磁化数据的可能性，以研究磁性特性与磁倍率响应之间的相互作用，例如在磁铁矿中的Verwey过渡中，或在铁磁体和抗铁磁体中的异常或拓扑厅效应中。最后，除了磁力测定法之外，我们还打算使用AC磁化敏感性测量来量化磁性秩序温度以及不同磁相的存在和范围。由于易感性的假想部分与磁耗散直接相关，因此AC敏感性测量还可以为分析磁波动现象的分析提供重要信息，磁波动现象目前正在Konstanz大学内的几个组进行研究。