Mechanics of Magnetic Shape-Memory Nanostructures

本计画的研究目标为阐明磁性形状记忆合金在奈米尺度下的力学与磁力学，并探讨磁性形状记忆合金在小型装置上的潜力与限制。四项目标包括：（i）纳米柱的力学和磁力学;（ii）薄膜的结构、相变和力学;（iii）纳米盘和纳米线的制造和磁力学;（iv）纳米尺度上磁畴和晶体孪晶的相互作用。纳米纤维、加工和热磁纳米机械特性的综合研究将把微观结构特征与其减小的尺寸所产生的独特性质联系起来。纳米纤维和加工技术将包括在各种衬底上的薄膜物理气相沉积、电子束光刻、聚焦离子束加工和热磁机械培训。微观结构和磁畴结构将采用各种扫描探针技术和透射电子显微镜技术进行表征。当前的器件、逻辑和存储器技术基于二进制单功能元件和易失性器件状态。这种具有多态性、多功能性和非挥发性的磁性形状记忆合金纳米结构具有很高的潜力，可以为小规模器件和记忆应用开辟新的途径。通过该项目雇用的学生将参与国际努力，其中包括访问奥地利和西班牙的合作机构。遵循博伊西州立大学的成功传统，几名本科生将参与研究工作。他们将在国际会议上展示成果，并撰写同行评审的期刊文章。外联活动以小学为对象，以吸引儿童从事科学和技术职业，包括定期访问小学教室。

The research goal of this project is to elucidate the mechanics and magneto-mechanics of magnetic shape-memory alloys at the nanoscale, and to explore the potential and limitations of magnetic shape-memory alloys in small-scale devices. Four objectives include: (i) Mechanics and magneto-mechanics of nano-columns; (ii) Structure, phase transformation, and mechanics of thin films; (iii) Fabrication and magneto-mechanics of nanodiscs and nanowires; (iv) Interaction of magnetic domains and crystallographic twins on the nano-scale. The combined study of nanofabrication, processing and thermo-magneto-nanomechanical characterization will link microstructural features to unique properties spawned by their reduced size. Nanofabrication and processing techniques will include physical vapor deposition of films on various substrates, electron-beam lithography, focused-ion-beam machining and thermo-magneto-mechanical training. The microstructure and magnetic domain structure will be characterized with various scanning probe techniques and transmission electron microscopy techniques. Current device, logical and memory technology is based on binary mono-functional elements and volatile device states. The multi-state, multifunctional and non-volatile magnetic shape-memory alloy nanostructures bear a high potential to open new pathways for small-scale devices and memory applications. Students employed through this project will engage in an international effort, which includes visits at partner institutions in Austria and Spain. Following a successful tradition at Boise State University, several undergraduate students will be included in research efforts. They will present results at international conferences and author peer-reviewed journal articles. Outreach activities are targeted towards grade schools to attract children to careers in science and technology and include regular visits of grade school classrooms.