超磁致伸缩薄膜难磁化轴方向动态特性研究

Study on dynamics of magnetostrictive thin film in hard axis

磁场驱动频率高是限制超磁致伸缩薄膜器件推广应用的关键因素之一,研究如何降低超磁致伸缩薄膜器件的磁场驱动频率对超磁致伸缩薄膜器件的推广应用将具有重要意义。在深入分析超磁致伸缩薄膜存在各向异性根本原因的基础上,结合薄膜磁致伸缩过程中磁畴的运动机理,提出只要能够克服超磁致伸缩薄膜中存在的退磁场,低磁场驱动频率下就可在难磁化轴方向获得更为优良动态特性的新思路。通过建立超磁致伸缩薄膜难磁化轴实验系统进行实验研究,结果表明通过施加合适的偏置磁场克服退磁场,可以使薄膜在难磁化轴方向产生响应优良的超谐共振,为低频驱动GMF器件的研制提供了一种新的思路。

High driving frequency of magnetic field is one of the key factors which restrict the popularization and application of giant magnetostrictive thin film device.The research on how to reduce the magnetic field driving frequency of giant magnetostrictive thin film device has important significance to the popularization and application of this kind of device.Based on the deep analysis of fundamental reason which cause giant magnetostrictive thin film existing anisotropy,combining the motion mechanism of domains in the magnetostrictive process of thin film,the paper puts forward a new idea that as long as it is able to overcome the demagnetizing field existing in giant magnetostrictive thin film,better dynamic characteristics can be obtained in the direction of hard magnetization axis under low driving frequency of magnetic field.An experiment is carried out in the hard magnetization axis experimental system of giant magnetostrictive thin film.The results show that it is able to make the thin film generate superharmonic resonance with excellent response through applying a suitable bias magnetic field to overcome demagnetizing field.The experimental results provide a new way for reducing the diving frequency of giant magnetostrictive thin film device.