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，涉及广泛的基础科学问题以及重要和新兴技术。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控制这些特性以产生新的功能。研究人员将新型材料工程和合成方法与先进的同步加速器技术相结合，用于三维应变和压电成像，以探测纳米级系统对磁场和电场扰动的响应。目标是获得纳米结构材料中应变的基本理解。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。 这种互动的方法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圣地亚哥大学（UCSD）和德尔马尔温斯顿学校的青年物理学家项目针对初中和高中学生的外展工作，以及通过UCSD的物理学生协会在本科阶段的外展工作。第一部份是探讨磁性过渡金属及过渡金属氧化物奈米材料的基本磁致伸缩特性。 在这样做的过程中，薄膜异质结构，核壳纳米线和纳米颗粒被成像的相干X射线衍射技术，以获得定量的三维纳米尺度的图像的磁致伸缩，然后链接的磁弹性响应的微观结构和微磁状态。然后，本研究使用应变来获得和优化纳米结构材料中的巨磁致伸缩。在下一阶段，材料被集成到器件中，以通过磁场和电场的组合来主动控制应变、磁性、传输和磁光响应。最后，应变的响应在超快的时间尺度上使用基于同步加速器的泵浦探测技术探测系统与电，磁或热脉冲和图像的响应与纳米聚焦和/或相干X射线衍射技术。

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.