GOALI: Nanoscale Characterization and Manipulation of Magnetoelastic Coupling and Magnetic Domains by Novel Quantitative Scanning Probe Microscopy

技术概要：该项目的目的是了解Galfenol或Fe-Ga合金中显著增强的磁致伸缩，其表现出比α-Fe高一个数量级的磁致伸缩应变，即使Ga是α-Fe。新型压磁力显微镜（PmFM）将通过华盛顿大学和庇护研究之间的合作，这将使磁弹性耦合和磁畴的定量表征和操作具有高灵敏度，高空间分辨率，并尽量减少与地形的串扰。磁致伸缩响应和磁畴的Galfenol将映射和操纵在纳米尺度上使用拟议的PMFM技术，并获得真实的空间磁致弹性响应将与底层的微观结构的Galfenol确定从详细的结构分析。还将对Galfenol的磁畴结构和演变以及转变的微结构进行建模和模拟，以将纳米级磁致伸缩响应和宏观磁致伸缩测量联系起来。通过紧密耦合的实验和理论研究，该项目将有助于澄清负责增强磁致伸缩Galfenol的微观机制。非技术摘要：磁致伸缩是指在铁磁材料中的磁场感应应变，Galfenol是一类新兴的结构磁致伸缩材料，具有优异的机械性能。它是有前途的广泛的应用在机械坚韧的环境中，如水下声纳换能器和阻尼或能量收集的机械振动，其中传统的超磁致伸缩材料是不合适的，因为他们的差的机械强度。该项目将有助于了解Galfenol增强磁致伸缩的微观机制，并可能指导开发具有更好性能的新结构磁致伸缩材料。还将开发一种新型的扫描探针显微镜技术，该技术可应用于研究各种磁性材料，其灵敏度和分辨率高于最先进的磁力显微镜。研究生和本科生将通过与工业界广泛合作的综合研究和教育进行培训，还将为高中学生和教师开展外联活动。

TECHNICAL SUMMARY: The objective of this project is to understand the dramatically enhanced magnetostriction in Galfenol, or Fe-Ga alloy, which exhibits magnetostrictive strain one order of magnitude higher than that of alpha-Fe, even though Ga is nonmagnetic. Novel piezomagnetic force microscopy (PmFM) will be developed through the collaboration between the University of Washington and Asylum Research, which will enable quantitative characterization and manipulation of magnetoelastic coupling and magnetic domains with high sensitivity, high spatial resolution, and minimized cross-talk with topography. Magnetostrictive response and magnetic domains of Galfenol will be mapped and manipulated at the nanoscale using the proposed PmFM technique, and the obtained real space magnetoelastic response will be correlated with the underlying microstructure of Galfenol determined from detailed structural analysis. Modeling and simulation of the configuration and evolution of magnetic domains and transforming microstructures of Galfenol will also be carried out to link the nanoscale magnetostrictive response and macroscopic magnetostriction measurement. Through the tightly coupled experimental and theoretical investigations, the project will help to clarify the microscopic mechanism responsible for the enhanced magnetostriction in Galfenol.NON-TECHNICAL SUMMARY: Magnetostriction refers to magnetic field induced strain in ferromagnetic materials, and Galfenol is an emerging class of structural magnetostrictive material with excellent mechanical properties. It is promising for a wide range of applications in mechanically tough environments, such as underwater sonar transduction and damping or energy harvesting of mechanical vibrations, in which conventional giant magnetostrictive materials are not suitable because of their poor mechanical strength. The project will help to understand the microscopic mechanism responsible for the enhanced magnetostriction in Galfenol, and potentially guide the development of new structural magnetostrictive materials with even better properties. A novel scanning probe microscopy technique will also be developed, which can be applied to study a wide range of magnetic materials with enhanced sensitivity and resolution over the state of art magnetic force microscopy. Graduate and undergraduate students will be trained through integrated research and education that involve extensive collaborations with industry, and outreach activities will also be developed for high school students and teachers.