压应力对Sm-Fe-B薄膜磁致伸缩性能的影响

Effects of compressive stress on the magnetostrictive characteristics of Sm-Fe-B films

摘要:

压应力对Sm-Fe-B磁致伸缩性能的改善有重要影响，但是其大小对磁致伸缩特性变化趋势的研究很少，而且还未见到压应力对磁各向异性影响的报道。本文利用特制夹具，使玻璃衬底在镀膜过程中受到不同应力作用，镀膜结束后，当玻璃衬底从夹具取下后，利用其恢复到原来状态，可以对稀土Sm-Fe-B薄膜产生压应力作用。通过调整夹具使衬底具有不同的预应力，可得到受到玻璃衬底不同压应力大小作用的薄膜样品。利用LK-G150激光微位移传感器与交变梯度磁强计（AGM）分别测试薄膜悬臂梁自由端偏转量与磁滞回线，以研究具有不同压应力对薄膜的磁致伸缩性能的影响，并且利用磁力显微镜（MFM）测试了薄膜样品垂直表面的磁畴分布情况。实验结果表明：受到压应力作用的薄膜易磁化轴都位于膜面内，以面内各向异性为主，磁畴结构基本分布在面内。随着压应力的增加，易磁化轴由膜面内的短轴转向膜面内的长轴，这一转变有利于器件的设计，但是磁畴在垂直膜面方向略有提高，薄膜的低场磁致伸缩性能也随着压应力的增大而有显著提高。

Abstract:

In this study, a set of Sm-Fe-B film with different compressive stress were prepared on substrate of different prestrain by Ion Beam Spurting Deposition (IBSD). The influence of compressive stress on the magnetic anisotropy and the magnetostriction in sputter-deposited amorphous Sm-Fe-B films were investigated. Films affected by compressive stress showed in-plane anisotropy and easy axis along the direction of stress was induced in the film with the increase of compressive stress . Magnetostriction of Sm-Fe-B films affected by compressive stress was improved in low magnetic field while saturation of magnetostriction decreased slightly. At the same time, the magnetostriction rised rapidly in low field measured in a field parallel to the film plane at room temperature with the growth of compressive stress. It has also been found that the magnetic domain component which was perpendicular to the film plane increased on a small scale, though the magnetic domain or the magnetic domain component parallel to film plane still existed dominant.