非晶合金带巨磁阻抗效应新型磁传感器研究

Study on New Magnetic Sensor Utilizing Giant Ma gneto-impedance Effect in Amorphous Ribbon

介绍了非晶合金带巨磁阻抗(GMI)效应的产生机理,对样品进行脉冲电流退火,获得了显著的GMI效应。实验分析了样品阻抗变化率随外加磁场、样品最大阻抗变化率随激励电流频率的变化关系。通过优化工作参数,提高了传感器的灵敏度、线性度和量程。在样品上均匀绕400匝线圈,以提供偏置磁场,将传感器的工作点移至线性区域。室温环境下,在激励电流频率f=1 MHz、有效值Irm s=25 mA、测量范围为±10 A/m时,传感器的测量精度优于0.96%,灵敏度为16.5 mV/Am-1,在弱磁检测领域具有很好的应用前景。

The mechanism of giant magneto-impedance （GMI） effect in amorphous alloy ribbon was presented. The sample that was annealed by impulse current can present obvious GMI effect. The external magnetic field dependence of the GMI ratio and the current frequency dependence of the maximal GMI ratio in amorphous ribbon were studied. The sensitivity and linearity of the sensor were improved by optimizing the working parameters. The operating point of the sensor can be moved by bias coils. The measurement accuracy is less than 0.96%, the sensitivity is 16.5 mV/Am^-l , and the linear measurement range is ±10 A/m at room temperature with the exciting sine current frequency of 1 MHz, and virtual value of 25 mA. Therefore, the sensor can be used in the weak magnetic field measurement with high sensitivity.