扫描探针显微镜对硬盘磁畴形态和表面形貌的研究

Studies on Magnetic Chips and Morphologies of Hard Disc by Scanning Probe Microscope

通过磁力显微镜(MFM),采用不同的提升高度(LSH)对垂直磁记录硬盘磁畴形态和表面形貌进行了实验;单独采用常规AFM对同一硬盘区域进行了形貌考察,用来和MFM得到的形貌进行比较。实验证明:MFM实验时设置的LSH必须小于等于给硬盘写入磁信息时磁头的飞行高度才能够清晰分辨磁畴的形态;另外,由于磁力的存在造成了在使用MFM同时测定硬盘的磁畴形态和表面形貌时,产生了严重失真的表面形貌假象,必须另外通过常规AFM检测才能准确确定硬盘的表面形貌和粗糙度数值;这种形貌假象也是磁信息的一种变相体现,可以通过硬盘类光滑样品的MFM失真形貌图来间接辅助确定其磁畴的形态分布。

In order to determine the lift scan height （LSH） of MFM in research of magnetic domain pattern and surface morphology of hard disc, and investigate the magnetic force influence on morphology in MFM, different LSHs are used in testing the perpendicular magnetic recording hard disc. In addition, the morphology of the same disk area is investigated by conventional tapping mode AFM. The experiments prove that the lift scan height of MFM must be set equal or less than the flying height of magnetic writing head to distinguish the magnetic domains pattern clearly, and the magnetic force produces severe illusion of morphology when detecting the magnetic domains and morphologies of hard disc by MFM at the same time. The accurate surface morphology and roughness of hard disc must be determined by AFM. This morphological illusion can be used to determine the magnetic domain patterns of samples as smooth as hard disc because the magnetic force information is embodied in it. It is pointed out clearly that LSH should be set in determining magnetic chips configuration of hard disc, as well as the influence exerted by magnetic force on morphologies in MFM experiment for the first time.