摘要
本文研究了交流电流的大小(I=0.2—20mA)和频率(f=1—1MHz)对具有横向畴结构的铁基纳米晶丝的巨磁阻抗效应形貌的影响.实验结果表明,样品的巨磁阻抗效应呈双峰特征,随着频率的增大,双峰的位置H=±Hm向高场移动;但随着电流的增大,双峰的位置逐渐向中心(H=0)收缩,甚至变成单峰位形.理论上一般认为,双峰的位置与横向各向异性场Hk相对应,即Hm=Hk.然而,我们发现这一结果只在交流电流很小的情况下才成立.从转动磁化过程中能量极小的原理出发,给出了双峰的位置为Hm=Hkcos3θ,θ为饱和磁化强度与丝轴的夹角.根据这一关系,定性地解释了实验结果.
The influence of AC current ( with amplitud of Iac = 0. 2—20 mA and frequency of f = 1 kHz—1 MHz) upon the profile of gian magnetoimpedance (GMI) effect of a Fe-based nanocrystalline wire with transverse domain structure have been investigated. The experiment indicates that the GMI effect of the sample exhibits a two-peak feature. With the increasing of f,the peak field Hm increases,while Hm decreases even to H = 0 when Iac increases. According to the current theoretical models,the peak field Hm should conrrespond to the transverse anisotropy field Hk,Hm = Hk. However,we found that this conclusion is correct only for the case of very small AC current. So a relationship Hm = Hk cos3θ,where θ is the angle between saturation magnetisation and the axis of wire,has been deduced by minimizing the energy in the process of magnetisation rotation. The experiments can be explained by this result.
出处
《物理学报》
SCIE
EI
CAS
CSCD
北大核心
2011年第3期630-634,共5页
Acta Physica Sinica
基金
河北省教育厅科技计划项目(批准号:Z2009143)资助的课题~~
关键词
巨磁阻抗效应
交流电流
铁基纳米晶丝
giant magnetoimpedance effect
AC current
Fe-based nanocrystalline wire