Zhu L, Jin F, Zhu Y Q, Wang J C, Dong K F, Mo W Q, Song J L, Ouyang J
School of Automation, China University of Geosciences, Wuhan, 430074, China.
Department of Electronic Science and Technology, Huazhong University of Science and Technology, Wuhan, 430074, China.
J Nanosci Nanotechnol. 2018 Dec 1;18(12):8195-8200. doi: 10.1166/jnn.2018.15799.
The stress-induced magnetic anisotropy can significantly affect giant magneto-impedance (GMI) effect of the soft magnetic film. This paper is devoted to the GMI effect of the single layer soft magnetic film implied without and with a stress. By simulating a physical model with MATLAB and COMSOL software, the impedance expression of the single layer soft magnetic film and the relation between external magnetic field and magnetic permeability are deduced. We observed that, without a stress, the sensitive region increased firstly and then decreased with the increasing of the excitation current frequency from 1 MHz to 200 MHz. While the film was subjected to the stress in the direction of the current with one end stressed, the stress on the film was gradually reduced from stressed end to free end. Also, the impedance change rate of the film changed when the stress was added, which is similar to the effect of adding a bias magnetic field on the film. More importantly, the addition of stress σ can induce the bias of the GMI measurement range and improve its sensitivity near zero magnetic fields. This may provide a new way for designing a GMI sensor with higher sensitivity and adjustable measurement range.
应力诱导磁各向异性会显著影响软磁薄膜的巨磁阻抗（GMI）效应。本文致力于研究单层软磁薄膜在无应力和有应力情况下的GMI效应。通过使用MATLAB和COMSOL软件模拟物理模型，推导了单层软磁薄膜的阻抗表达式以及外部磁场与磁导率之间的关系。我们观察到，在无应力情况下，随着激励电流频率从1 MHz增加到200 MHz，敏感区域先增大后减小。当薄膜在电流方向上一端受力而受到应力时，薄膜上的应力从受力端到自由端逐渐减小。此外，施加应力时薄膜的阻抗变化率发生改变，这类似于在薄膜上施加偏置磁场的效果。更重要的是，应力σ的施加可以引起GMI测量范围的偏移，并提高其在零磁场附近的灵敏度。这可能为设计具有更高灵敏度和可调节测量范围的GMI传感器提供一种新方法。
