单缝衍射法测TbDyFe的磁致伸缩系数

Measurement of Magnetostrictive Coefficient of TbDyFe by Single Slit Diffraction Method

本文根据夫琅禾费衍射原理,把TbDyFe和2个刀片组合成1个单缝,在不同的磁场强度下,TbDyFe在磁场中产生微小的变化,从而引起衍射条纹的变化;利用自制电控位移平台扫描单缝衍射图样,用多组衍射条纹间的位移变化量来计算出缝宽变化量,从而求出TbDyFe材料的磁致伸缩系数,完成TbDyFe材料磁致伸缩系数的自动测量.实验证明此方案快速准确.

In this paper,according to the Fraunhofer’s diffraction principle,TbDyFe and two blades are combined into a single slit.Under different magnetic fields,TbDyFe changes slightly,which can cause changes in the diffraction fringes.With using the self-made electronically controlled displacement platform,the single-slit diffraction patterns are scanned and then the slit width change can be calculated according to the changes of multiple sets of diffraction stripes,and at last the magnetostrictive coefficient of TbDyFe material is obtained.The automatic measurement of the magnetostrictive coefficient of TbDyFe material is achieved.The experiments indicate that the method works fast and accurate.