Magnetoelastic Interactions in Giant Magnetostriction Multilayers for Adaptive Micro-systems Transducers

项目摘要：主要研究夹在高磁化软磁体（如Fe-Co）之间的Tb-Fe或Sm-Fe薄膜的高应变敏感性和低开关场的“巨”磁致伸缩。由于这些多层材料中应力和磁化之间的层间相互作用，理解和控制磁弹性耦合是这些研究的关键目标。为了理解磁弹性耦合，正在开发一个综合能量函数，将所有磁、机械和耦合能结合起来。溅射沉积多层膜作为层厚度和层数的函数，并在沉积后进行应力退火以优化其磁弹性行为。利用分析电子显微镜、x射线衍射和扫描探针显微镜对薄膜的磁性结构和微观结构进行了表征。优化后的薄膜作为微机电系统（MEMS）和生物微机电系统（Bio-MEMS）的自适应元件正在进行测试。除了由于磁弹性相互作用而观察到的丰富新现象外，这些研究还对快速发展的MEMS和生物MEMS领域产生了重大影响。例如，具有高动态响应的高效微开关、激光束偏转器、流体射流偏转器、阀门、超声波马达、微夹持器和微泵。教育影响包括研究生和本科生的积极培训和参与，以及来自布法罗地区内城高中的高中生。

PIs: R. C. Wetherhold and Harsh Deep Chopra, State University of New York at BuffaloProposal Number: 0099830Proposal Title: Magneto-Elastic Interactions in Giant Magnetostriction Multilayersfor Adaptive Micro-Systems TransducersProject Abstract: Research is focused on high strain susceptibility and low switching field "giant" magnetostriction of Tb-Fe or Sm-Fe films, which are sandwiched between high magnetization soft magnets, such as Fe-Co. Due to inter-layer interactions between stress and magnetization in these multilayers, understanding and controlling favorably the magneto-elastic coupling is a key objective of these studies. An overall energy function is being developed for the combination of all magnetic, mechanical, and coupling energies, in order to understand the magneto-elastic coupling. Multilayers are being sputter deposited as a function of layer thickness and number of bilayers, with post-deposition stress annealing to optimize their magneto-elastic behavior. Films are being characterized for their magnetic structure and microstructure using analytical electron microscopy, x-ray diffraction, and scanning probe microscopy. Optimized films are being tested as adaptive components of micro-electro-mechanical systems (MEMS) and Bio-MEMS. In addition to the richness of new phenomena that are being observed due to magneto-elastic interactions, these studies impact significantly the rapidly evolving fields of MEMS and bio-MEMS. Examples include highly efficient micro-switches, laser beam deflectors, fluid jet deflectors, valves, ultrasonic motors, micro-grippers and micro-pumps, with high dynamic response. Educational impact includes active training and participation of graduate and undergraduate students, as well as high school students from Buffalo area inner city high schools.