基于磁光克尔效应的磁光材料表征方法

发布时间：2018-01-19 08:15

本文关键词： 磁光克尔效应各向异性材料磁光椭偏技术磁光克尔成像系统磁畴成像效果优化　出处：《山东大学》2017年硕士论文　论文类型：学位论文

【摘要】：随着磁光器件如磁光存储器件、磁光传感器件、自旋电子器件等在信息、医疗、国防等技术领域的广泛应用,对高性能磁光材料的需求也日益提升,提升现有磁光材料的性能以及探索新型的磁光材料均需要高效的磁光材料表征方法。基于磁光效应的各种磁光表征技术通过测量光与磁光材料相互作用产生的新的光学各向异性实现对磁光材料器件的无损检测,而且磁光表征技术具有高测试精度、高灵敏度、高时间分辨率和高空间分辨率以及高强的磁场兼容性等优点,因此可以为磁光材料性能的研究和应用提供先进的测量工具。本文主要对基于磁光克尔效应的磁光材料表征方法进行了研究。对各向异性磁性材料的纵向磁光克尔表征理论进行了研究,建立了各向异性磁光材料的纵向克尔理论模型,给出了各向异性材料的纵向磁光克尔偏转角表达式。并利用该公式对各向异性Co薄膜材料的磁光性能进行了模拟分析,分析结果表明各向异性Co薄膜的磁光性能优于各向同性Co薄膜材料,这为基于Co薄膜材料的磁光器件的研究提供了理论基础。磁光椭偏技术结合了椭偏理论和磁光克尔理论,可以同时对磁光材料的光学参数和磁光参数进行表征。本文利用自制的磁光椭偏系统对CoFeB薄膜的磁光性能进行了测量,得到了 CoFeB薄膜的光学常数以及磁光耦合系数,实验结果对CoFeB材料在磁性隧道结,高密度磁存储等领域的应用具有积极的意义。对磁光材料的磁性机理进行研究可以更好的理解磁光材料的本质从而提高磁光材料的性能,而对磁畴的结构和行为进行研究是探索材料磁性机理最直接的方法。本文对宽视场磁光克尔成像系统的结构进行了构建,并提出了一种通过优化磁光克尔成像系统中的偏振器方位角对磁光克尔成像系统的对比度和信噪比进行优化的方法,为直观的研究磁光材料的磁畴结构行为提供了先进的测量工具。
[Abstract]:With the wide application of magneto-optic devices such as magneto-optical storage devices, magneto-optic sensing devices, spin electronic devices in information, medical, national defense and other technical fields, the demand for high-performance magneto-optic materials is also increasing. It is necessary to improve the properties of existing magneto-optic materials and to explore new magneto-optic materials. New methods of magneto-optic characterization based on magneto-optic effect are introduced by measuring the interaction between optical and magneto-optic materials. Optical anisotropy is used to realize nondestructive testing of magneto-optic materials. Moreover, magneto-optical characterization technology has the advantages of high testing accuracy, high sensitivity, high temporal resolution and high spatial resolution, and high magnetic compatibility. In this paper, the characterization method of magneto-optic materials based on magneto-optic Kerr effect is studied. The longitudinal magneto-optic grams of anisotropic magnetic materials are studied. The theory of representation is studied. The longitudinal Kerr model of anisotropic magneto-optic materials is established. The expression of longitudinal magneto-optic Kerr deflection angle of anisotropic materials is given, and the magneto-optic properties of anisotropic Co thin films are simulated and analyzed by using the formula. The results show that the magneto-optic properties of anisotropic Co thin films are better than that of isotropic Co thin films. This provides a theoretical basis for the study of magneto-optic devices based on Co thin film materials. Magneto-optical ellipsometry combines ellipsometry theory with magneto-optical Kerr theory. The optical and magneto-optical parameters of magneto-optic materials can be characterized at the same time. The magneto-optical properties of CoFeB thin films have been measured by self-made magneto-optical ellipsometry system. The optical constants and magneto-optic coupling coefficients of CoFeB thin films are obtained. The experimental results show that the CoFeB films are connected in magnetic tunnel junctions. The research on magnetic mechanism of magneto-optic materials can better understand the essence of magneto-optic materials and improve the properties of magneto-optic materials. The study of magnetic domain structure and behavior is the most direct way to explore the magnetic mechanism of materials. In this paper, the structure of wide-field magneto-optic Kerr imaging system is constructed. A method is proposed to optimize the contrast and SNR of magneto-optic Kerr imaging system by optimizing the azimuth of polarizer. It provides an advanced measurement tool for the direct study of magnetic domain structure behavior of magneto-optic materials.
【学位授予单位】：山东大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TB383.2;O482.55

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