淬态非晶FeNiCrSiB/Cu/FeNiCrSiB三明治薄带的巨磁阻抗特性

Giant Magneto-Impedance Properties of Quenched Amorphous FeNiCrSiB/Cu/FeNiCrSiB Sandwiched Ribbon

研究了淬态非晶FeNiCrSiB/Cu/FeNiCrSiB三明治薄带样品的巨磁阻抗(GMI)特性。该三明治薄带具有十分显著的GMI效应,在0.5 MHz频率下其纵横向GMI比分别达到282%和408%。磁畴结构观察表明,三明治薄带由于横向磁路闭合,使得沿带轴方向主导的180°条形畴向横向产生约10°偏转。分析了三明治薄带磁电阻、磁感抗、有效磁导率的变化与GMI效应的关系,发现在40 Hz^10 MHz测试频率范围内,样品的磁感抗部分对GMI效应起主导作用,这缘于三明治结构降低了损耗,显著提高了材料有效磁导率、增强了磁电感效应,受控于三明治薄带有效磁导率变化的磁电感效应是其GMI效应的主要特征。

The giant magneto-impedance（GMI） properties of FeNiCrSiB/Cu/FeNiCrSiB sandwiched ribbon were studied. The results show that the sandwiched ribbon has remarkable GMI effects. The maximum values of the longitudinal and transverse GMI ratios are 282% and 408%, respectively, at the frequency of 0.5 MHz. The orientation of 180° stripe domains tend towards the ribbon axis. Due to the transverse closed magnetic flux loop of sandwiched ribbon, a 10 degrees deflection of stripe domains to the transverse direction is observed. Besides, the relationship of magneto-resistance, magneto-inductance, and effective permeability to GMI were analyzed. It is found that in the frequency range of 40 Hz-10 MHz, the magneto-inductance plays a decisive role. It is attributed to the special sandwiched structure, which reduces energy losses, improves effective permeability significantly and then enhances magneto-inductance effect. The magneto-inductance effect controlled by effective permeability is the principal feature of the GMI.