三明治结构FeNi/Cu/FeNi多层膜巨磁阻抗效应研究

Giant magneto-impedance in sandwiched FeNi/Cu/FeNi films

摘要: 采用MEMS技术在玻璃基片上制备了三明治结构FeN i/Cu/FeN i多层膜,在1～40 MHz范围内研究了FeN i/Cu/FeN i多层膜中的巨磁阻抗效应特性。当磁场H_a施加在薄膜的长方向时,巨磁阻抗效应随磁场的增加而增加,在某一磁场下达到最大值,然后随磁场的增加而下降到负的巨磁阻抗效应。在频率为5MHz时,巨磁阻抗效应在磁场H_a=800 A/m时达到最大值26.6%。巨磁阻抗效应的最大值及负的巨磁阻抗效应与多层膜中磁各向异性轴的取向及发散有关。另外,当磁场施加在薄膜的短方向时,薄膜表现出负的巨磁阻抗效应,在频率5 MHz、磁场H_a=9600 A/m时,巨磁阻抗效应可达-15.6%。

Abstract: Sandwiched FeNi/Cu/FeNi films were prepared by MEMS（Microelectromechanical Systems） technique on glass substrate.The giant magneto-impedance（GMI） effect was investigated in the frequency range of 1~40 MHz.With magnetic field H_a applied along the longitudinal direction of the sample,the GMI ratio increases with H_a,reaching a positive maximum value at a certain field and then decreases to the negative GMI ratio with further increase of H_a.At a frequency of 5 MHz,the positive maximum GMI ratio is 26.6% for H_a=800 A/m.In addition,with the magnetic field applied along the transverse direction,the GMI ratio is negative and a negative GMI ratio,-15.6% is obtained at 5 MHz for H_a=9600 A/m.