Electron spin resonance spectrometer

在奥格斯堡大学的电子相关与磁性中心（ECM），实验物理V的主席专注于研究具有新功能的强相关磁性材料。感兴趣的材料有：受挫磁铁、低维自旋系统、磁电化合物、斯基米子载体、磁性Weyl半金属和非常规超导体。这些材料中的大多数都是在椅子上生长并仔细地进行结构和磁性表征的，然后再用电介质和光谱学、原子力显微镜以及电子和核磁共振技术等先进方法对它们进行研究。在磁共振方面，电子自旋共振（ESR）发挥着核心作用，无论是对新磁性材料的一般表征，作为样品纯度的检查，还是对局部电子和磁性质的深入研究，以识别微观相互作用。ESR通常直接探测感兴趣的自旋系统，这决定了被研究材料的物理性质。因此，在许多情况下，实验工作远远超出了标准表征，例如，为了确定磁相变的临界指数或为了研究磁各向异性，必须根据样品温度和样品在磁场中的方向遵循详细的测量方案。每个磁性样品的大量强制性测量迫切需要一个新的强大的ESR光谱仪，因为现有的20多年的机器严重超载，最近需要经常维护。我们申请了一台ESR光谱仪，用于x波段（9.4 GHz）和q波段（34 GHz）的连续波工作。与现有设备相比，微波桥和信号处理单元的现代技术可以提高数据记录的分辨率和速度。在实验室里，已经有一个用于高达1.8特斯拉磁场的电磁铁和几个用于控制氦和氮温度的低温恒温器。此外，目前的光谱仪将继续使用，以便为多达8个用户提供足够的操作时间。拟议的新的ESR光谱仪将能够加速和加强目前和计划中的分析新多功能材料的活动。这对于我们在Transregio“TRR 80”（“从电子相关性到功能性”）和优先计划“SPP 2137”（“Skyrmionics”）内成功延续项目至关重要，也是实现提案中描述的各种计划项目的先决条件。

At the Center for Electronic Correlations and Magnetism (ECM) at the University of Augsburg, the chair of Experimental Physics V focuses on the study of strongly correlated magnetic materials with new functionalities. Materials of interest are e.g. frustrated magnets, low-dimensional spin systems, magnetoelectric compounds, skyrmion hosts, magnetic Weyl semimetals and unconventional superconductors. Most of these materials are grown and carefully structurally and magnetically characterized in the chair, before they are studied by advanced methods like dielectric and optical spectroscopy, atomic force microscopy, as well as electron and nuclear magnetic resonance techniques.Regarding magnetic resonance, electron spin resonance (ESR) plays a central role, both for the general characterization of new magnetic materials as a check of sample purity and for the deeper study of local electronic and magnetic properties to identify microscopic interactions. Often ESR directly probes the spin system of interest, which determines the physics of the material under investigation. Therefore, in many cases the experimental effort goes far beyond standard characterization, e.g. for determination of critical exponents at magnetic phase transitions or for investigation of magnetic anisotropy, whereby detailed measurement protocols have to be followed dependent on sample temperature and orientation of the sample in the magnetic field. This vast number of mandatory measurements for each magnetic sample urgently demands a new powerful ESR spectrometer, as the existing more than 20 years old machine is heavily overloaded and recently requires frequent maintenance.We apply for an ESR spectrometer for continuous-wave operation at X-band (9.4 GHz) and Q-band (34 GHz) frequencies. The modern technology of the microwave bridge and the signal processing unit allows an improved resolution and higher velocity in data recording as compared to the existing device. An electromagnet for magnetic fields up to 1.8 Tesla and several cryostats for helium- and nitrogen temperature control are already available in the laboratory. In addition, the present spectrometer will continue to be used to allow for enough operation time for the up to eight users.The proposed new ESR spectrometer will allow to accelerate and intensify the current and planned activities in the analysis of new multifunctional materials. This is essential for the successful continuation of our projects, within the Transregio “TRR 80” (“From Electronic Correlations to Functionality”) and the Priority Program “SPP 2137” (“Skyrmionics”), and it is prerequisite for the realization of various planned projects, described in the proposal.