Tb_(0.3)Dy_(0.7)Fe_2合金磁畴偏转研究

Study on magnetic domain deflection in Tb_(0.3)Dy_(0.7)Fe_2 alloy

研究了Tb_(0.3)Dy_(0.7)Fe_2合金在压磁和磁弹性效应中的磁畴偏转和磁导率特性.基于Stoner-Wolhfarth模型能量极小原理,绘制了自由能与磁畴偏转角度的关系曲线,研究了压应力和磁场载荷作用下磁畴角度的偏转特性,计算分析了不同载荷作用下磁畴偏转的磁导率特性,并与实验数据进行比较论证.研究表明,应力和磁场的作用都将使磁畴方向[111]和[(?)]发生角度跃迁,直观有效地解释了材料巨磁致伸缩效应的机理;应力和磁场作用下磁畴的偏转将使材料磁导率呈减小趋势,其中磁场能对磁导率的影响大于应力能,这一现象在小载荷作用下尤为明显.实验结果表明,磁导率的计算数据与实验数据符合得较好,验证了计算方法的正确性.理论分析对Terfenol-D磁畴偏转模型的完善和磁化过程中磁滞回线的绘制非常有意义.

The characteristics of magnetic domain deflection and permeability under piezomagnetic and magnetoelastic effects in Tb0.3Dy0.TFe2 alloy are studied in this paper. Based on the minimal value principle of Stoner-Wolhfarth model, the curve of free energy versus domain deflection angle is analyzed, and the angle deflections of magnetic domain under differ compressive stresses and magnetic fields are discussed. The calculational and experimental results of permeability under stress and magnetic field loads are used to confirm the analysis of domain deflection in ally. These results indicate that the magnetic domains [111] and [iii] each have a transition effect of angle deflection with the increase of stress and magnetic field, which can be used to explain the huge magneticostric- tive mechanism of Terfenol-D. Also, permeability has a negative relation with stress and magnetic field, and the influence of magnetic energy on permeability is greater than the stress energy effect, especially under small loads. The experimental results of permeability are in a good agreement with the calculations confirming the validity of calculation and analyzsis. The above computations have a significant guidance for analyzing and studying the magnetic domain deflection model and hysteresis in Terfenol-D.