磁性薄膜的高频性能表征技术研究

发布时间：2018-06-29 16:07

本文选题：动态磁化 + 铁磁共振　；参考：《电子科技大学》2015年硕士论文

【摘要】：随着磁存储行业近年来的迅速发展,市场对磁存储材料的记录速度要求越来越高,这就将MRAM等超快磁记录器件的操作频率推到了GHz频段。在这个高频段下,磁弛豫成为器件性能极为重要的一方面,人们对磁阻尼机理的深入研究产生了兴趣,为了对磁化进动的转换进行最优化,磁性材料阻尼因子的具体系统控制变得十分重要。因此研究材料高频动态磁化过程的表征技术有着重要意义。本文在对目前高频动态磁性能表征技术的发展状况的调研基础上,确立了使用基于共面波导与矢量网络分析仪的新型铁磁共振测试作为表征手段,以建立宽频带铁磁共振自动化测试系统为研究目的。研究的主要内容包括:(1)基于新型铁磁共振测试原理,完成了宽频带铁磁共振测试系统硬件组建,其中核心内容是采用电磁仿真软件HFSS设计制作了适用于本系统的新型共面波导测试夹具。经测试,夹具微波性能满足系统需求。(2)基于虚拟仪器技术,使用LabVIEW开发了自动测试软件,通过磁场自动控制,矢量网络分析仪的自动设置与读取以及测试数据的自动化显示与存储三大模块,实现了全自动铁磁共振测试。(3)研究分析了宽带铁磁共振测试的数据处理技术,建立了测试S21曲线与铁磁共振曲线的关系。并使用LabVIEW编制了数据自动处理系统,其中集成了目前广泛使用的相移洛伦兹拟合与Fano拟合,实现了一键调入数据得到铁磁共振线宽与共振磁场。(4)在实际测试中,对比了两种拟合方法的拟合结果,分析了铁磁共振曲线形状对拟合结果的影响,并指出Fano拟合具有更广的适用范围。在实际测试中,本文搭建的宽带铁磁共振测试系统精度较高,重复性好,而且克服了传统铁磁共振测试频率限制的缺点,可在任意频率下测试得到铁磁共振线宽,从而获取阻尼因子,为材料高频动态磁化提供了全面可靠的表征,是研究磁化动力学的有力工具。
[Abstract]:With the rapid development of magnetic storage industry in recent years, the market demands higher and higher recording speed of magnetic storage materials, which pushes the operating frequency of MRAM and other ultra-fast magnetic recording devices to the GHz band. In this high frequency band, magnetic relaxation has become one of the most important aspects of the device performance. In order to optimize the conversion of magnetic precession, people are interested in the further study of the mechanism of magnetic damping. It is very important to control the damping factor of magnetic material. Therefore, it is of great significance to study the characterization of high frequency dynamic magnetization process of materials. In this paper, based on the investigation of the development of high frequency dynamic magnetic properties characterization technology, a new ferromagnetic resonance test based on coplanar waveguide and vector network analyzer is established as a means of characterization. The purpose of this study is to establish a broadband automatic ferromagnetic resonance test system. The main contents are as follows: (1) based on the new ferromagnetic resonance testing principle, the hardware structure of the wideband ferromagnetic resonance testing system is completed. The core content is the design and manufacture of a new coplanar waveguide testing fixture using electromagnetic simulation software HFSS. The test results show that the microwave performance of the fixture meets the requirements of the system. (2) based on the virtual instrument technology, the automatic test software is developed with LabVIEW, and the magnetic field is automatically controlled. The automatic setting and reading of vector network analyzer and the automatic display and storage of test data are three modules to realize automatic ferromagnetic resonance testing. (3) the data processing technology of wideband ferromagnetic resonance testing is studied and analyzed. The relationship between the measured S 21 curve and the ferromagnetic resonance curve was established. An automatic data processing system is developed with LabVIEW, in which the widely used phase-shifted Lorentz fitting and Fano fitting are integrated, and the ferromagnetic resonance linewidth and resonance magnetic field are obtained by inserting the data with one key. (4) in the actual test, The effect of the shape of ferromagnetic resonance curve on the fitting results is analyzed, and the Fano fitting is pointed out to be more suitable. In the actual test, the wideband ferromagnetic resonance testing system built in this paper has high precision and good repeatability, and overcomes the shortcoming of the traditional ferromagnetic resonance testing frequency limit, and can be measured at any frequency to obtain the ferromagnetic resonance linewidth. Therefore, the damping factor is obtained, which provides a comprehensive and reliable characterization for the high frequency dynamic magnetization of materials and is a powerful tool for the study of magnetization dynamics.
【学位授予单位】：电子科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TB383.2

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