DEVELOPMENT OF MULTILA YERED FILMS WITH ULTRA-HIGH MAGNETOSTRICTION AND SOFT MAGNETIC PROPERTIES AND THEIR APPLICATIONS FOR MICRO-MAGNETIC

TbFe和TbHoFe非晶薄膜：采用射频溅射法制备了TbFe和tbho - fe体系的薄膜，研究了薄膜的磁性和磁弹性。Tb_<40>Fe_<60>和Tb_<27>Ho_<13>Fe_<60>非晶态薄膜由于具有较大的磁致伸缩和相当软的面内磁性能，在磁声应用中非常有吸引力。研究了热退火对其磁弹性性能的影响。结果表明，热退火有助于提高其低场磁致伸缩响应。这被认为主要是由于退火消除了内应力。指出了退火制备纳米晶TbFe_2相的另一种可能性。TbFe/FeB非晶多层膜：采用射频溅射法制备了具有TbFe/FeB/TbFe夹层结构和TbFe/FeB结构的多层膜，研究了其性能。结果表明，在室温下，当层间层厚度在薄膜总厚度的10 ~ 40%范围内时，夹层膜具有较软的面内磁化和较大的磁致伸缩。TbFe/FeB多层膜的磁弹性性能随着TbFe和FeB层数的叠加而变差。发现Tb和B的热扩散是导致这一问题的原因，有必要进一步研究如何制备多层膜而不存在这一问题。非晶薄膜作动元件：采用大磁致伸缩、软内磁化的Tb-Ho-Fe非晶薄膜制备悬臂式作动元件。采用厚度为12.5mum的卡普顿衬底，致动器位移达到100mum。

TbFe and TbHoFe amorphous films :Single films with Tb-Fe and Tb-Ho-Fe systems were fabricated by rf sputtering, and their magnetic and magnetoelastic properties were studied. Tb_<40>Fe_<60> and Tb_<27>Ho_<13>Fe_<60> amorphous films were found to be very attractive for magnetoacoustic applications owing to their large magnetostriction and considerably soft inplane magnetic properties. The effect of thermal annealing on their magnetoelastic properties were also investigated. The results suggest that the thermal annealing is useful for improving their low-field magnetostrictive response. This is considered to be mainly due to relief of internal stresses by annealing. Another possibility of formation of nanocrystalline TbFe_2 phase by annealing was also pointed out.TbFe/FeB amorphous multilayr films :Multilayr films with TbFe/FeB/TbFe sandwich structures and TbFe/FeB structures were formed by rf sputtering and their properties were investigated. The results revealed that a considerably soft inplane magnetization and a huge magnetostriction could be obtained in the sandwich films at room temperature, provided that the thickness of FeB interlayr was within the range of 10-40% of the total film thickness. As for TbFe/FeB multilayr films, their magnetoelastic properties were deteriorated by stacking many numbers of TbFe and FeB layrs. Thermal diffusion of Tb and B were found to be responsible for it, and further studies are necessary by fabricating multilayr films without such a problem.Actuator elements with amorphous films :Cantilever-type actuator elements were constructed using the Tb-Ho-Fe amorphous films with large magnetostriction and soft inplane magnetization. By using Kapton substrate with 12.5mum thickness, the actuator showed a displacement of 100mum.