磁敏感器复合薄膜巨磁阻抗效应的产生与增强机理研究

Analysis on the Cause and Enhancement of Giant Magneto-Impedance(GMI) Effect in Multilayered Thin-Film Structures in Magnetic Sensors

磁性层/导电层/磁性层结构合薄膜比单层膜具有更强的巨磁阻抗(GMI)效应,但其GMI效应产生和增强的机理尚不完全清楚.本文从经典电磁理论出发,建立了复合薄膜GMI效应的理论模型,利用模型仿真了典型的磁敏感器复合膜Co-SiB/Cu/CoSiB的GMI特性及其内部电流的分布.通过研究得到结论:复合结构中的"类趋肤效应"是产生GMI效应的主要原因;各层之间的相互电磁作用和导电层的高电导率特性是使复合结构GMI效应得到加强的原因.

Multilayered thin-film structures consisting of soft magnetic layers and well conducting spacers exhibit stronger GMI(giant magnetoimpedance) effect than single layer film,whose mechanism is however obscure.The theoretical model of GMI effect in multilayered structures is established upon the Classical electromagnetic theory,with which,the GMI curve and current-density distribution of a typical multilayered structures(CoSiB/Cu/CoSiB) magnetic sensor is obtained.Conclusion shows that the 'Similar Skin Effect' in multilayered film structure is the primary cause for the GMI effect,and both the electro-magnetic interactions between different layers and the high conductivity of the conductive spacer count as important factors for the enhancement of GMI effect in multilayered structures.