Research on magnetization structure stability of magnetic thin films

用磁力显微镜研究了温度对钴合金记录介质磁化结构的影响。本文还尝试了用超高压分子束外延技术在单晶衬底上外延制备Co薄膜，研究了具有fcc和hcp晶体结构的Co薄膜的基本磁性。得到以下结果.通过在低于10 μ Pa的真空度下冷却样品和采用低磁矩探针，MFM的观测分辨率提高到15 - 20 nm<-4>。高密度磁记录介质（面密度为80 - 110 Gb/in^2）的记录磁化结构的变化在-100-300 ℃的温度范围内已被成功地可视化。阐明了纵向和垂直记录介质在加热时磁化结构变化的差异.发展了一种MFM数据分析技术，用于研究纳米尺度下磁化结构的变化.采用超高真空分子束外延技术在氧化物单晶衬底上制备了Co薄膜，研究了薄膜生长过程中fcc缓冲层和衬底温度对Co薄膜晶体结构的影响。可以控制Co薄膜的晶体结构为fcc或hcp。利用外延生长的Co薄膜系统地研究了磁性与晶体结构的关系.上述研究成果在国内会议上发表2次演讲，在国际会议上发表3次演讲，并在学术期刊上发表5篇论文。

The influence of temperature on the magnetization structure of Co-alloy recording media is studied by using a magnetic force microscope (MFM). Preparation of epitaxial Co thin films on single crystal substrates is also tried by using an UHV-MBE to investigate the basic magnetic properties of Co thin films with fcc or hcp crystal structure. The following results are obtained.1. The MFM observation resolution is improved up to 15 -20 nm level, by cooling the sample under a vacuum lower than 10^<-4> Pa and by employing low magnetic moment probe-tips.2. The variation of recorded magnetization structure of high-density magnetic recording media, 80 - 110 Gb/in^2 areal density, has been successfully visualized in a temperature range between -100 - 300 C. The difference in magnetization structure variation upon heating between longitudinal and perpendicular recording media has been clarified.3. An analysis technique of MFM data is developed to investigate the nanometer scale variation of magnetization structure.4. Epitaxial Co thin films are prepared on oxide single crystal substrates by using an UHV-MBE and the effects of fcc-buffer layer and the substrate temperature during film deposition on the crystal structure of Co thin film are clarified. It is possible to control the Co thin film either with fcc or hcp crystal structure. The relationship between the magnetic properties and the crystal structure is systematically studied by using the epitaxial Co thin films.5. The above research results were presented as 2 talks in domestic conferences, 3 talks in international conferences, and were submitted as 5 papers to academic journals.