Tb_(0.27)Dy_(0.73)Fe_(1.98)在恒场下磁致伸缩应变──随压力变化曲线的诠释

Explanation on the Magnetostriction vs Stress Curve of Tb 0 27 Dy 0 73 Fe 1 98

本文用标准应变片法研究了Ｔｂ０．２７Ｄｙ０．７３Ｆｅ１．９８在压应力下的磁致伸缩特性，由于样品中存在多个晶粒，所以没有发现“巴克豪森跳跃”现象，但是λ－Ｐ曲线却表现出了一定的规律性：在低场下曲线单调下降，当Ｈ＝５０ｋＡ／ｍ时在Ｐ０＝１３．６ＭＰａ处曲线开始出现一峰值，且Ｐｏ不随外场的增加而变化。文中用自由能极小原理对这一现象作了诠释。

The magnetostrictive property under applied stress of Tb 0 27 Dy 0 73 Fe 1 98 was studied using standard gauge The jump effect was not discovered because of several grains in the sample However, the λ P curve has the following characteristics Under low field λ decreases with the increase of P ; When H =10kA/m,the curve begins to show one peak at P 0=13 6MPa, P 0 does not change when applied field is increased This phenomenon is ex plained by free energy criterion P 0 was found to be proportional to the anisotropy field H a: P 0= μ 0 M s H a3 λ s