RESEARCH ON PERPENDICULAR SINGLE-POLE-TYPE HEAD FOR ULTRA HIGH DENSITY MAGNETIC RECORDING BY USING NUMERICAL ANALYSIS

本课题对垂直记录系统中最重要的部件之一的单极头进行了数值分析。最初的目标是每平方英寸1太比特（Terabits/in^2）。我们已经研究了SPT头部结构，以实现此密度和超越。主要研究结果如下：1.基于有限元模拟，研究了400 Gb/in^2单极型磁头的设计。示出了为该面密度产生足够场所需的条件。为了达到这个密度，各种介质被认为是和写入磁道宽度，擦除频带，信噪比的，和写入的位模式来自LLG模拟。2.比较了离散轨道介质和连续介质的记录性能。尾部屏蔽增加了头部磁场梯度，导致更尖锐的过渡和更高的SNR。对于两种类型的介质，最佳拖尾屏蔽间隙被确定为30 nm。使用这样的写入头并且在没有相邻轨道擦除的条件下，在1700 kfci的线密度下，离散轨道介质SNR比连续介质高1.5 dB。3.执行对整个磁性材料进行微磁性处理的LLG计算。记录领域的各种极尖结构进行了研究。有人发现，存在一个最佳的非零喉高度，最大限度地提高记录场强。尾屏蔽被认为是有效的，以获得一个更大的记录场梯度。4.进行了热分析，并在SPT头元件的温升推导出各种条件下。由于商业软件缺陷，未对温升引起的变形分析进行研究。

In this scientific research, single-pole-type head, one of the most important components in perpendicular recording, was investigated by numerical analysis. The original goal was set at 1 Terabits per square inch (Terabits/in^2). We have investigated the SPT head structure to achieve this density and beyond. Here are the results obtained :1.A single-pole-type head design for 400 Gb/in^2 based on FEM simulations was investigated. The conditions required to generate a sufficient field for this areal density were shown. To reach this density various media were considered and written track widths, erase bands, SNR's, and written bit patterns were derived from LLG simulations.2.The recording performance of discrete track media and continuous media was compared. Trailing shields increase the head field gradient, leading sharper transitions and higher SNR. The optimum trailing shield gap was determined to be 30 nm for both types of media. Using such a write head and subject to the condition of no adjacent track erasure the discrete track media SNR was 1.5 dB higher than the continuous media at a linear density of 1700 kfci.3.LLG calculation that treats the whole magnetic material micromagnetically was performed. The recording fields are investigated for various pole tip structures. It was found that an optimum non-zero throat height exists that maximizes recording field strength. Trailing shield was found to be effective with regard to obtaining a larger recording field gradient.4.Thermal analysis was carried out and the temperature rise in the SPT head element derived for various conditions. Deformation analysis due to temperature rise was not investigated because of commercial software bugs.