反正切垂直磁化MR头读出波形的理论分析

A Theoretical Analysis of Readback Voltage of Arctangent Perpendicular Magnetization with an MR Head

目前温式磁盘机的位密度已达20kbPI～50kbPI;道密度可达1000TPI～2000TPI.进一步提高面密度特别是道密度还有很大的发展潜力,但一个主要障碍在于传统的感应式磁头读出的信号的信噪比随着道密度的进一步提高而过分微弱,MR头是能满足高密度记录的新型磁头.磁阻材料用于磁头中检读信号首先是由Hunt提出的.近几年来,国外对MR头的实用化进行了许多研究.而到目前为止,国内尚未研制出实用的MR头.本文对数字磁记录中MR头的读出过程进行了理论分析,为MR头的研制提供了一定的理论依据.

A newly developed MR readout head for a vertical magnetic recording system, which utilizes the reluctance effect in a thin magnetic film deposited onto a nonmagnetic substrate, is described. A theoretical basis for the optimization design of the system is presented. The readback voltage of an isolated arctangent perpendicular magnetization with an MR head is calculated. According to the results of calculation, the readback voltage is independent of the disk velocity. The effects of the MR head depth w, the disk thickness d, as well as the distance d between the head and the disk on the readback waveform can be analyzed with the formula given in this paper and the optimization value of W, and d can be obtained.