"STUDY OF STRUCTRE AND PROPERTY OF MAGNETIC FILMS MADE WITH M.B.E."

利用分子束外延技术制备了铂钴人工晶格薄膜，通过原位RHEED分析研究了生长速度和衬底温度对薄膜结构的影响，确定了合适的成膜条件。对于在硅衬底上形成薄膜，以厚度为20 nm、温度为473K的铂层作为缓冲层是比较合适的条件。通过原子力显微镜对薄膜表面结构的精确测量，对薄膜的边界应变和一致性进行了评价。通过薄膜X射线衍射仪对薄膜的精细结构进行了评价，并尝试对薄膜作为人工晶格的堆积性能进行了量化。通过与超高真空隧道连接到分子束外延室的XPS分析，确定了形成垂直于薄膜方向的纳米级周期的成分调制。VSM测试结果表明，人工晶格周期和成膜条件对薄膜的磁特性有影响。通过MFM对磁畴结构的观察，发现随着Co层厚度的增加，磁畴尺寸减小。我们用静磁能和磁壁能之和的磁能来解释这一现象。用边界元法计算了磁壁为90度和45度的磁畴的静磁势分布。将MFM的计算结果与计算值进行了比较，讨论了人工晶格薄膜的磁畴结构。改进了霍尔磁测量装置，用于测量5kOe磁场下的巨磁阻率。证实了薄膜的晶界结构对磁特性的影响。讨论了用溅射装置制备的颗粒状结构薄膜的磁特性。用退火法研究了晶界结构变化对样品的磁特性和X-射线衍射谱的影响。

I made artificial lattice films of Pt/Co with the MBE.I valued the effect of the growth speed and the substrate temperature on the film structure by the "in situ" RHEED analysis, and I decided a suitable film formation condition. For the formation films on silicon (Ill) substrate, it was valued as a suitable condition to make Pt layer of 20 nm thickness, of 473K temperature as a buffer layer. I evaluated the boundary strain and the consistency of films with the precise measurements of AFM on surface structure of films. By the thin film X-ray diffraction, I evaluated fine structure of films and I attempted, to quantify the stacking property of films as an artificial lattice. With XPS analysis, which is connected with ultra high vacuum tunnel to MBE chamber, I made sure the composition modulation of nm order period that is formed normal directions to the film. The result of VSM measurement showed that the period of artificial lattice and formation condition of films affect the magnetic characteristic. By observation of magnetic domain structure with MFM, I found that domain size decreases with the increasing of Co layer thickness. We explained this phenomenon with the evaluation of magnetic energy as sum of static magnetic energy and magnetic wall energy. We calculated static magnetic potential distribution with BEM for the magnetic domains with magnetic wall of 90 degree and 45 degree. We compared the result of MFM with the calculated value arid discussed magnetic domain structure of artificial lattice films.We improved the Hall magnetic measurement device to measure giant magnetic resistivity in 5kOe magnetic field. We confirmed that boundary structure of films affects magnetic characteristic. We discussed the magnetic characteristic of the granular structure films prepared with sputtering device. We evaluated the magnetic characteristic and X-ray diffraction profile under the alternation of boundary structure by the annealing.