磁畴观测系统研究及近场光学探针的制备
文献类型：学位论文
| 作者 | 杨永斌 |
| 学位类别 | 博士 |
| 答辩日期 | 2009 |
| 授予单位 | 中国科学院上海光学精密机械研究所 |
| 导师 | 徐文东 |
| 关键词 | 纳米磁性材料 磁畴观测系统 巨磁阻磁头 近场光学探针 静动结合化学腐蚀法 |
| 其他题名 | Research on the observing and measuring system of magnetic domain and fabrication of near-field optical probe |
| 中文摘要 | 目前，纳米磁性材料的应用非常广泛，己经从传统的技术领域发展到高新技术领域，从单纯磁学范围，拓展到与磁学相关的交叉学科领域，其广度和深度比其他功能材料都要大得多。磁畴结构及其运动规律直接决定了磁性材料的物理性质和应用方向，因此纳米尺度的磁畴检测是进行纳米磁性材料研究的前提条件。与此同时，现有的磁畴检测技术都存在一定的不足之处，如分辨率较低、灵敏度较低、装置比较复杂或者昂贵等。因此对纳米磁性材料的进一步研究，需要一个更加完善的磁畴检测技术。 近场光学探针是扫描近场光学显微镜的核心器件。现有的近场光学探针制备技术都存在一定的缺点，如制备探针的重复性较差，制备的探针的分辨率较低或通光效率较低或者装置较复杂等。因此发展一种装置比较简单且制备探针的重复性较高的近场光学探针制备技术从而制备出分辨率和通光效率较高的探针，并进一步拓宽扫描近场光学显微镜的应用范围具有重要意义。 本论文的主要目的是设计和搭建一种分辨率和灵敏度较高、装置比较简单且便宜的磁畴观测系统，以及一种装置比较简单且制备探针的重复性较高并能制备高分辨率和通光效率的近场光学探针的装置。本论文的内容主要包括三部分。第一部分是新的磁畴观测系统的设计与搭建。第二部分是静动结合化学腐蚀法制备近场光学探针的理论分析。第三部分是新的近场光学探针制备装置的设计与搭建。 首先，我们利用巨磁阻磁头设计并搭建了一个新的磁畴观测系统。该系统主要由计算机、控制机箱、巨磁阻磁头、数字源表、离子风机、xy向扫描器、z向扫描器、电控位移台、四维调整架和光学显微镜及CCD摄像头组成。系统中的巨磁阻磁头是商用的，其中的巨磁阻薄膜的尺寸仅为几十纳米，因此其极易被静电损坏。我们着重研究了其被静电损坏的机制。根据静电产生的三种模式，分别采取了一些措施，解决了巨磁阻磁头极易被静电损坏的问题。利用我们搭建的这个系统，我们进行了记录在纳米磁性材料上的磁畴观测，得出了初步的实验结果。此外，我们还利用磁力显微镜观测了这些记录在纳米磁性材料上的磁畴，且将我们的系统所得的初步结果与磁力显微镜所得结果进行了比较，比较后的结果证实了我们系统的可行性。 其次，我们对静动结合的化学腐蚀法制备近场光学探针的原理进行了理论分析。首先，根据光纤移动速度对氢氟酸腐蚀液面的影响情况，我们具体分为了五种情况详细的分析了该法制备近场光学探针的过程，并得出了各种情况下，制备的近场光学探针的长度及锥角的函数表达式；然后我们又数值模拟并分析了腐蚀时间及光纤移动速度对所制备的近场光纤探针的长度及锥角的影响情况。根据上述分析，我们得出了该法制备探针的机理，即先由静态部分将光纤腐蚀成一个锥台的形状；在此形状的基础上，再利用光纤的移动速度对氢氟酸腐蚀液面的影响情况，将光纤制备成各种结构的光纤探针。 最后，我们设计并搭建了一个自动化腐蚀法制备探针的装置。该装置主要由计算机、控制电路板、步进电机、手动平移台、精密平移台、横梁、支架、光纤夹、聚四氟乙烯烧杯、米勒钳、底座及带孔的盖子组成。利用该装置，我们进行了近场光学探针的实验制备，制备出了各种结构的光纤探针。然后我们用磁控溅射法在光纤探针表面进行了金属银的镀膜，并将镀膜后的光纤探针利用扫描电镜进行了观察。扫描电镜所得出的结果证实了我们搭建的这个装置的可行性。此外，利用这些结果，我们详细的分析了探针制备的各个条件对所制备的探针结构参数的影响情况，实验上所得出的结果与理论分析所得结果基本一致。 |
| 英文摘要 | The application scope of nanomagnetic materials is very extensive now. It has been developed from traditional technology to high-tech field, and expanded from simplex magnetics to interdisciplinary field related to magnetics. The width and depth of its application are larger than those of other functional materials. The physical properties and application directions of nanomagnetic materials depend on the structures and motion laws of magnetic domains, so the detection of magnetic domains in nanoscale is the precondition to investigate the nanomagnetic materials. However, the existing technologies of detecting magnetic domain have some drawbacks, such as low resolution, low sensitivity, high cost of the apparatus and its complexity. Therefore, further investigation on nanomagnetic materials calls for more advanced techniques of detecting magnetic domain. The near-field optical probe is the core of the scanning near-field optical microscope. However, the existing technologies of fabricating the near-field optical probe have some drawbacks, for example, the repeatability of fabricating the near-field optical probe is low, the resolution or optical transmission efficiency of the near-field optical probe is low, and the apparatus is relatively complex. Therefore, it is very significant for forming probes with high resolution and optical transmission efficiency, and extending further the application range of the scanning near-field optical microscope to develop a technology of fabricating the near-field optical probe with simple apparatus and high repeatability. The main aims of this thesis are to design and build a new observing and measuring system of magnetic domains with high resolution and sensitivity, and simple apparatus, and to devise an apparatus of fabricating the near-field optical probe with simple apparatus, by which the high resolution and optical transmission efficiency of the optical probes can be obtained. This thesis consists of mainly three parts. The first part is the design and build of the new observing and measuring system of magnetic domain. The second part is the theoretical analysis of forming the near-field optical probe by a new chemical etching method combining static etching and dynamic etching. The third part is the design and build of the new apparatus for forming the near-field optical probe. First, we design and set up a new observing and measuring system of magnetic domain with high resolution according to the characteristics of the giant magnetic resistor (GMR) magnetic head. The system consists of computer, crate controller, GMR magnetic head, digital source meter, ion blower, x-y scanner, z scanner, displacement mount with electrical control, 4D adjusting mount, optical microscope and CCD camera. The GMR magnetic heads used here are commercial ones, and they are very easy to be damaged by the electrostatic discharge (ESD) because of the small nanoscale size of GMR film. First, many attentions are paid to explore the mechanisms leading to the ESD damage of the GMR magnetic head. And then, effective measures are taken to prevent the ESD damage of the GMR magnetic head according to the three modes of producing ESD. Finally, the magnetic domain recorded in nanomagnetic material is observed and measured by use of the new system we design. In addition, we also detect the magnetic domain in nanomagnetic material using magnetic force microscope, and compare the results obtained by our system with the results obtained by magnetic force microscope. It shows that our system and the magnetic force microscope give very similar results, which proves the validity of our system. Second, we analyze theoretically the principle of forming the near-field optical probe by a new chemical etching method combining static etching and dynamic etching. According to the influence of fiber moving velocity on the surface of the liquid hydrofluoric acid, we analyze in detail the process of fabricating the probes by this method in five conditions, and obtain the functional expression concerning the length and cone angle of the near-field optical probe in these conditions. And then, the influence of the etching time and moving velocity of the optical fiber on the length and cone angle of the near-field optical probe is obtained by numberical simulation and analysis. Based on the above analysis, the mechanism of forming probes by this method is obtained. That is, the optical fibers are first etched to be cone frusta, and then on the basis of the cone frusta, the optical fibers can be formed to be probes with different structures according to the influence of the fiber’s moving velocity on the surface of the liquid hydrofluoric acid. In the end, we design and set up an automatic apparatus of forming probes by use of etching method. The apparatus consists of computer, control electric board, motor, manual translation stage, precision translation stage, beam, bracket, fiber rack, Teflon beaker, miller fiber optic striper, pedestal, Teflon cover with hole. First, the fiber probes with different structures are fabricated by use of the apparatus we design. Then, the silver films are coated on the fabricated fiber probes, and the coated probes are observed by use of the scanning electron microscope. The results obtained with the scanning electron microscope prove the validity of our apparatus. Furthermore, the influence of the fabricating conditions on the structure parameters of the formed probes is obtained. The experimental results are in close agreement with the theoretical ones. |
| 语种 | 中文 |
| 源URL | [http://ir.siom.ac.cn/handle/181231/15277]  |
| 专题 | 上海光学精密机械研究所_学位论文 |
| 推荐引用方式 GB/T 7714 | 杨永斌. 磁畴观测系统研究及近场光学探针的制备[D]. 中国科学院上海光学精密机械研究所. 2009. |
入库方式： OAI收割
来源：上海光学精密机械研究所
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