软磁薄膜的高频磁性测试方法研究及其在坡莫合金薄膜研究中的应用

发布时间：2018-06-17 16:49

本文选题：复数磁导率 + 高频测试　；参考：《兰州大学》2017年硕士论文

【摘要】：近年来,随着社会经济的迅速发展和生活质量的提高,人们对高科技产品的要求也越来越高,这也促使电子科学技术和元器件的迅速发展,尤其是向微型化、薄膜化、集成化和高频化的方向发展。以通讯频段为例,最早使用的通讯系统的频率一般为900MHz和1.8 GHz,也就是GSM标准,或者称为第二代(2G)移动通讯系统,发展到目前广泛使用的通讯频段已经达到了3 GHz和4 GHz。这也对应用于其中的磁性功能材料提出了更高的要求。软磁材料因其在电感和变压器中的广泛应用而受到关注。随着元器件的工作频率的提高,对软磁薄膜材料的高频性能也提出了相应的要求,特别是软磁薄膜材料的高频磁导率和共振频率等。因此,对软磁薄膜的高频磁性进行准确地表征是该领域亟需解决的重要问题之一。本论文主要围绕软磁薄膜的高频磁性测量与评估这一问题,在对国内外软磁薄膜的高频磁性测量方法调研和比较的基础上,提出了基于电磁感应的无需定标的高频磁性测量方法。另外通过高频磁性测量方法系统地研究了坡莫合金薄膜的高频磁性。本论文的主要内容如下:1、系统地总结了利用短路微带线测量软磁薄膜的高频磁性的方法,并且对其进行了改进。利用高频仿真软件对短路微带线夹具进行设计并加工组装,通过优化测试夹具的尺寸参数和优化仪器参数实现了对软磁薄膜在宽频段的磁谱的准确测量。另外还提出了一种基于电磁感应原理的无需定标的磁谱计算方法,在分析过程中只需要给出薄膜样品的尺寸大小。另外,研究了直角型的共面波导(Coplanar waveguide,简称CPW)测试夹具对软磁薄膜的磁谱的测试结果,并与短路微带线夹具的测试结果进行对比。如果在测量磁谱的过程中,给软磁薄膜样品施加一个直流偏置磁场,那么就构成了用矢量网络分析仪(Vector Network Analyzer,缩写VNA)测量铁磁共振的测试方法,可以简称为VNA-FMR测试方法。2、利用Top-down方法制备的不同厚度的坡莫合金薄膜。利用VNA-FMR测试方法分别研究了微波磁场在垂直和平行条纹方向上激励坡莫合金薄膜时的条纹畴结构的高频磁性。对沿着条纹畴方向的伪动态单轴各向异性做了详细地研究。通过建立一个简单的物理模型推导出动态各向异性场的起源。此外,通过磁力显微镜的实时观测和VNA-FMR方法研究了条纹畴结构在外磁场作用下的转动性质。通过转角度的磁谱测量研究了条纹畴结构在任意角度下的高频磁性。通过建立唯象的物理模型发现起始磁化率与转动角度之间的关系可以体现出条纹畴结构中的磁矩分布情况。因此,我们也获得了一种分析转角度高频磁谱的理论方法和拟合公式。利用真空热处理方法研究了坡莫合金薄膜中交换劲度系数的变化。实验结果表明热处理后的坡莫合金薄膜中条纹畴宽度增大,矫顽力变小,起始磁导率变大等,通过随机各向异性模型分析,以及高频磁谱分析和微磁学模拟得出真空热处理可以增强坡莫合金薄膜的交换劲度系数。3、利用图案化对坡莫合金薄膜的高频磁性进行调控。通过VNA-FMR方法研究了坡莫合金薄膜表面的Fe65Co35圆盘阵列修饰对其高频磁性的影响。结果表明,不管是方形阵列或者是矩形阵列,不同圆盘密度的表面图案化修饰可以有效地对坡莫合金薄膜的阻尼进行微调,调控范围是0.008-0.013之间,而且还可以在不同的外加磁场下调控阻尼,这个结果对于实际的应用是很有价值的。此外,又通过VNA-FMR方法研究了反盘结构的坡莫合金薄膜的高频磁性。结果表明反盘结构的坡莫合金薄膜具有比较丰富的共振模式。4、基于自旋霍尔效应通过电学方法来调控软磁薄膜的铁磁共振。首先,通过VNA-FMR方法研究了Pt/Permalloy双层薄膜中的自旋泵浦效应,以此证明在我们制备的Pt/Permalloy双层薄膜样品中自旋流可以通过其界面互相注入。在测量样品磁谱的过程中给样品通入毫安级别的直流电流。结果表明,利用自旋霍尔效应产生的自旋流对坡莫合金薄膜的铁磁共振的阻尼系数有很小程度的调控作用。
[Abstract]:In recent years, with the rapid development of the social economy and the improvement of the quality of life, the demand for high-tech products is becoming higher and higher. This also promotes the rapid development of Electronic Science and technology and components, especially in the direction of miniaturization, film, integration and high frequency. The frequency of the communication band is the first frequency of the communication system. The rate is generally 900MHz and 1.8 GHz, that is, the GSM standard, or the second generation (2G) mobile communication system, and the widely used communication band has reached 3 GHz and 4 GHz., which also raises higher requirements for the magnetic functional materials used in it. With the increase of the working frequency of the components, the high frequency performance of the soft magnetic thin film materials is also required, especially the high frequency permeability and resonance frequency of the soft magnetic thin film materials. Therefore, the accurate characterization of the high frequency magnetic properties of the soft magnetic thin film is one of the most important problems to be solved in this field. On the basis of investigation and comparison of high frequency magnetic measurement methods of soft magnetic thin films at home and abroad, a high frequency magnetic measurement method based on electromagnetic induction is proposed, and the high frequency magnetic properties of permalloy thin film are systematically studied by high frequency magnetic measurement. The main contents of this paper are as follows: 1, the method of measuring the high frequency magnetic properties of the soft magnetic thin film by short circuit microstrip line is systematically summarized and improved. The short circuit microstrip line fixture is designed and fabricated by using the high frequency simulation software. The soft magnetic field is realized by optimizing the size parameters of the test fixture and optimizing the instrument parameters. The accurate measurement of the magnetic spectrum in the wide band is also given. In addition, a magnetic spectrum calculation method based on the electromagnetic induction principle is also proposed. In the analysis process, only the size of the film sample is required. In addition, the magnetic spectrum of the Coplanar waveguide, CPW test fixture for the soft magnetic thin film is studied. The test results are compared with the test results of the short circuited microstrip line fixture. If a DC bias magnetic field is applied to the soft magnetic film samples in the process of measuring the magnetic spectrum, a test method for measuring ferromagnetic resonance with the vector network analyzer (Vector Network Analyzer, abbreviated VNA) can be referred to as the VNA-FMR test method for short. .2, the different thickness of permalloy films prepared by Top-down method is used to study the high frequency magnetic properties of the stripe domain structure when the microwave magnetic field is excited in the vertical and parallel stripe directions. The pseudo dynamic uniaxial anisotropy along the direction of the stripe domain is studied in detail. A simple physical model is established to derive the origin of the dynamic anisotropic field. In addition, the rotational properties of the stripe domain structure under the external magnetic field are studied by the real time observation and VNA-FMR method of magnetic force microscope. The high frequency magnetic properties of the fringe domain structure at any angle are studied by the magnetic spectrum measurement of the rotating angle. The physical model found that the relationship between the initial magnetic susceptibility and the rotation angle can reflect the magnetic moment distribution in the fringe domain structure. Therefore, we have also obtained a theoretical method and a fitting formula for analyzing the high frequency magnetic spectrum of the rotating angle. The results show that the width of stripe domain in the permalloy film after heat treatment increases, the coercivity becomes smaller and the initial permeability becomes larger. Through the analysis of the random anisotropy model, the high frequency magnetic spectrum analysis and the micromagnetic simulation, the vacuum heat treatment can enhance the exchange stiffness coefficient.3 of the permalloy film, and use the patterning to make the permalloy thin. The influence of the Fe65Co35 disc array modification on the surface of the permalloy film on the high frequency magnetic properties is studied by VNA-FMR method. The results show that the surface patterning of different disk densities can effectively adjust the damping of the permalloy film, regardless of the square array or rectangular array. The control range is between 0.008-0.013, and the damping can be controlled under different external magnetic fields. This result is of great value for practical application. In addition, the high frequency magnetic properties of the ppermalloy thin film with reverse disk structure are studied by VNA-FMR method. The results show that the permalloy film with the reverse disk structure has a relatively rich resonance mode. .4, based on the spin Holzer effect, regulates ferromagnetic resonance in a soft magnetic thin film by an electrical method. First, the spin pump effect in a Pt/Permalloy double layer thin film is studied by VNA-FMR method, which proves that the spin flow can be injected into the Pt/Permalloy bilayer thin film samples. The results show that the spin current produced by the spin Holzer effect has a small control effect on the damping coefficient of the ferromagnetic resonance of the permalloy film.
【学位授予单位】：兰州大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O484

【相似文献】