Novel Magnetic Shape Memory Alloy Thin Films for Sensor and Actuator Applications

该奖项的研究目标是研究新型磁性形状记忆合金薄膜，并将这些薄膜用作传感器和执行器的主干。特别是，一类新颖的镍基Heusler合金薄膜将被用作模型系统并进行实际应用测试，该薄膜能够提供高频响应以及由于塞曼能量诱导的相变而产生的高致动应变。这一目标将通过以下科学方法来实现：(1)研究相分离对相变的影响；(2)探索和定制薄膜中的残余应力以调节相变；(3)了解场致应变和可逆相变的尺寸效应；(4)通过双层薄膜演示磁场传感的概念；以及(5)通过薄膜制造致动器。如果成功，这项研究的好处将包括阐明场诱导跨多个长度尺度形状变化的基本磁微结构机制，以及用于传感器和执行器应用的新型磁性形状记忆合金薄膜。该项目将显著改进能够快速和可逆变形、阻尼和无源发电的有源传感系统的设计。其次，它将促进以磁性薄膜为重点的本地学习环境。活动将包括创建活动材料的教学模块，通过获得博士学位的途径让未被充分代表的群体参与。德克萨斯农工大学的奖学金计划，7-12年级纳米材料的实验室演示模型，以及本科生研究人员的参与。第三，与洛斯阿拉莫斯国家实验室和桑迪亚国家实验室集成纳米技术中心的科学家通过现有的用户项目进行合作，将为研究生提供在这些先进研究中心和实验室工作的机会。

The research objective of this award is to investigate novel magnetic shape memory alloy thin films and use these films as the backbone of sensors and actuators. In particular, a class of novel Ni-based Heusler alloy films, which is capable of delivering high frequency response as well as high actuation strain due to Zeeman energy induced phase transformations, will be used as a model system and tested for real applications. This objective will be achieved by using the following scientific approaches: (1) investigate the influence of phase segregation on phase transformations; (2) explore and tailor residual stress in films to tune phase transformations; (3) understand the size effect on field induced strain and reversible phase transformations; (4) demonstrate the concept of magnetic field sensing via bilayer films; and (5) fabricate actuators via membranes. If successful, the benefits of this research will include elucidation of fundamental magneto-microstructural mechanisms of field-induced shape change across multiple length scales, and a new class of magnetic shape memory alloy films for sensor and actuator applications. The project will significantly improve the design of active sensing systems capable of fast and reversible deformation, damping and passive power generation. Second, it will promote a local learning environment focusing on magnetic thin films. Activities will include creation of teaching modules of active materials, involvement of underrepresented groups through the ?Pathway to Ph.D.? fellowship program at Texas A&M University, laboratory demonstration models in nanomaterials for grades 7-12, and involvement of undergraduate researchers. Third, collaborations with scientists at the Center for Integrated Nanotechnologies, at Los Alamos National Laboratory and Sandia National Laboratory through the existing user project will provide graduate student opportunities to work at these advanced research centers and laboratories.