自旋阀多层膜磁化翻转场的调控和磁电阻特性

用磁控溅射方法制备Ta/CoFe/Fe/Au/Fe/IrMn/Ta和Ta/CoFe¹/Au/CoFe²/IrMn/Ta两种多层膜结构的自旋阀，并优化各功能层的溅射参数有效调控了磁化翻转场和磁电阻特性。根据TEM确定了样品多层膜的微观结构和膜厚，使用VSM和加磁场四探针法分别测量了样品的磁滞回线和磁电阻(MR)特性曲线。结果表明，样品中隔离层Au的厚度与MR值之间存在振荡衰减的关系；而钉扎层、自由层和被钉扎层的厚度直接影响各膜层的矫顽力和饱和磁化强度等磁学性能，进而改变MR值。各层厚度为6/6/3.8/6/9/6 nm的Ta/CoFe¹/Au/CoFe²/IrMn/Ta结构自旋阀，具有最佳的MR值。

Magnetization Reversal Field and Magneto-Resistor of Spin Valve

Two kinds of spin valve composed of multilayered films of Ta/CoFe/Fe/Au/Fe/IrMn/Ta and Ta/CoFe¹/Au/CoFe²/IrMn/Ta were deposited respectively on oxidized silicon wafer by high vacuum magnetron sputtering. Their magneto-resistor characteristics and magnetization reversal fields were tailored by selectively adjusting the processing parameters for each of the function layers. The microstructure and thickness of the multilayered films were characterized by means of TEM. The hysteresis loops and magneto resistance (MR) curves were measured by VSM and four-probe measurement tests. Results show that there exists a relationship of vibration attenuation for the MR values with the thickness of the middle isolation layer Au. Namely, with the increase of the thickness of the Au layer, the vibration attenuation weakened. The coercive force and saturation magnetization of the multilayered films were determined by the thickness of each different function layers, which then alter the MR values directly. There was a best MR value for the multilayered structure of Ta/CoFe¹/Au/CoFe²/IrMn/Ta with the following film thickness for each layer: 6/6/3.8/6/9/6 nm.