Strain-induced modification of nanoscale materials properties

非技术描述：纳米磁学是科学中最活跃的领域之一，涉及广泛的基本科学问题以及重要和新兴的技术。新的功能需要在纳米空间尺度和亚纳秒时间(时间)尺度上控制磁序。在该项目中，正在研究纳米结构磁性材料中应变和磁性的相互作用以及如何控制这些性能以产生新的功能。研究人员正在将新的材料工程和合成方法与先进的三维应变和压电成像同步加速器技术相结合，以探测纳米系统对磁场和电场扰动的响应。其目标是对纳米结构材料中的应变有一个基本的了解。该项目将受益于与国际、国家用户设施和工业科学家的密切合作。这种互动方式为研究生和本科生提供了重要的教育和研究生就业机会。此外，该项目还包括通过加州大学圣地亚哥分校(UCSD)和德尔马尔的温斯顿学院(Winston School)针对初中生和高中生的推广工作，以及通过加州大学圣地亚哥分校的学生物理学会在本科生层面进行的推广工作。技术细节：该项目的第一部分探索磁性过渡金属和过渡金属氧化物纳米材料的基本磁致伸缩响应。在此过程中，薄膜异质结构、核壳纳米线和纳米颗粒被相干X射线衍射技术成像，以获得磁致伸缩的定量三维纳米级图像，然后将磁弹性响应与微结构和微磁状态联系起来。这项研究然后利用应变来获得和优化纳米结构材料的超磁致伸缩。在下一阶段，材料将被集成到设备中，以利用磁场和电场的组合来主动控制应变、磁、传输和磁光响应。最后，基于同步加速器的泵浦-探测技术在超快时间尺度上的应变响应用电、磁或热脉冲探测系统，并用纳米聚焦和/或相干X射线衍射技术成像响应。

NON-TECHNICAL DESCRIPTION: Nanomagnetism is one of the most active areas in science with a wide range of fundamental scientific problems as well as important and emerging technologies. New functionality requires control of magnetic order at the nanometer spatial scale and sub-nanosecond temporal (time) scale. Within this project, the interplay of strain and magnetism in nano-structured magnetic materials and the control of these properties to yield new functionality are being studied. Researchers are combining novel materials engineering and synthesis approaches with advanced synchrotron techniques for three-dimensional strain and piezoelectric imaging to probe the response of nanoscale systems to perturbation by magnetic and electric fields. The goal is to gain a fundamental understanding of strain in nanostructured materials. This project will benefit from strong collaborations with international, national user facility and industrial scientists. This interactive approach provides important educational and post-graduate career opportunities for both graduate and undergraduate students. In addition the project includes outreach efforts aimed at middle-school and high-school students via the Young Physicist Program at the University of California San-Diego (UCSD) and The Winston School in Del Mar, and outreach at the undergraduate level, via UCSD's Society of Physics Students.TECHNICAL DETAILS: The first part of the project probes the fundamental magnetostrictive response of nano-materials of magnetic transition metals and transition-metal oxides. In doing so, thin-film heterostructures, core-shell nanowires and nanoparticles are being imaged by coherent X-ray diffraction techniques to obtain quantitative three-dimensional nano-scale images of the magnetostriction and then link the magneto-elastic response to the microstructure and micromagnetic states. This research then uses strain to obtain and optimize giant magnetostriction in nanostructures materials. In the next stage, materials are being integrated into devices to actively control the strain, magnetic, transport and magneto-optical responses with a combination of magnetic and electric fields. Finally, the response of strain at the ultrafast timescales using synchrotron-based pump-probe techniques probes the systems with electric, magnetic or thermal pulses and images the response with nano-focused and/or coherent X-ray diffraction techniques.