接近表面磁力显微镜成像方法的研究

The investigation of near-surface magnetic force microscopy

在当今信息社会时代,需要存储的信息总量正在急剧增加。与光存储技术和半导体存储技术相比而言,磁记录技术占领着几乎90%的存储市场。磁力显微镜（magnetic force microscope,MFM）的发展与磁记录工业密切相关。然而,从1987年至今,MFM的分辨率仍然停留在50～10 nm的水平,传统思路已经很难再实现突破。本论文基于MFM探针的窄带-频率调制机理,发展接近表面磁力显微镜方法,实现对纳米结构中磁畴状态的超高分辨率成像。该工作的关键在于合理利用MFM探针的窄带-频率调制机理,优化设计动态信号处理模块,精确控制探针-样品间距（5 nm以下）,独立分离磁力像和表面像（磁力像为交流信号,原子力像为直流信号）,由此测量和解释纳米尺度磁畴结构。该方面的工作对于纳米磁畴结构的设计、核心磁性器件的研究起到非常关键的作用,为下一代磁记录技术的发展提供了新型的有力工具。

The observation of nanoscale magnetic domains with atom resolution is very important to the development of nextgeneration magnetic products. In this paper,we developed a new method for near surface observation of the magnetic domains with ultra-high resolution. Based on the nanometer operation in MFM system and precise control of the tip-sample distance,the observation of nanoscale magnetic domains in perpendicular magnetic recording media was performed. The present method can be applied to investigate the microscopic magnetic domain structures in a variety of magnetic materials and devices,such as high-density recording media,recording and writing heads,ultrathin films,nanoparticles,patterned elements,as well as other magnetic features and nanostructures,which opens up the possibility for directly observing the dynamic magnetic features,and provides a useful tool for the development of next-generation magnetic recording systems.