线性自旋阀磁头的材料性能及结构参数优化

Optimizing of the Materials Properties and Structure Parameters of Giant Magnetoresistance Spin-valve Head

优化材料性能参数和自旋阀巨磁阻磁头的结构参数是微磁器件实用化的关键．本文基于建立的物理计算模型，首先利用传输线方法和微磁学理论对铁磁自由层中信号场和磁化强度分布进行了计算，优化了材料性能参数；其次讨论了磁头结构尺寸和磁参数对信号场和饱和磁感应强度的影响；最后将自旋阀巨磁阻磁头传感单元作为有源磁电阻放人前端放大电路，对输出电压。二次谐波及线性区间进行模拟，发现在缝宽g1＋g2≤0．7。线性偏电流10～50mA范围内，自旋阀磁头相对记录介质有线性信号输出。

Optimizing the materials properties and structure parameters of giant magneto-resistance head are of key importance to application. Based on the physics computation model in this work, we firstly calculated the signal field and magnetization distribution in free layer using transmittance line model and micro-magnetic theory, and then we discussed the effect of size and magnetic parameters on the magnetic flux and signal field; finally, we put the head on a suitable front-end electric circuit which acts as a variation magneto-resistance, and analyzed the output voltage, harmonic signal and line range. The simulated results show that output signal has good linear characteristic with respect to the medium recording signal in a wide range of gap length （g1＋g2≤0.7）. The optimal value of sensing current should be selected between 10 mA and 50 mA.