Correlation Among the Size, Atomic Arrangement, and Magneto-Optical Properties in Rare Earth Nanocrystals

技术摘要：本项目旨在确定一类海森堡铁磁纳米材料——稀土硫系纳米晶体的几何和磁光效应是如何相互关联的。利用氮气气氛下的单源前驱体热裂解工艺，制备了尺寸在小于2.0 nm（量子限制）至约20 nm（纳米晶体）之间的EuS、EuO和EuTe单分散纳米晶体。纳米晶体的磁性和磁光性质将作为晶体尺寸、晶体边界特性和晶体内部局部原子分离的函数来研究。这些研究将通过磁、光学和x射线衍射技术进行。不同的任务和项目活动的设计目标是鼓励代表性不足的群体参与科学，为科学基础设施做出贡献，并将科学与教育结合起来。教育/研究项目将允许从高中到研究生水平的学生参与。这些是特别的NSF吗？范德比尔特大学科学拓展中心高中暑期实习。该项目的智能基础设施有望帮助开发新的磁性和磁光纳米器件。纳米技术不断产生重要的和意想不到的结果，其中许多是为了人类的利益。它的潜力仍在开发中，在可预见的未来，它的发展可能会继续下去。随着结构和设备变得越来越小，制造它们的材料的性质也发生了变化。在很多情况下是戏剧性的？不同于物质的性质。了解这些性质对于继续发展技术和理解越来越小尺度的物理现象非常重要。在这方面，该项目旨在确定几何和磁光效应是如何在一类铁磁纳米材料中相互关联的：稀土硫属化合物。当使用本项目的特定方法制备时，这些材料形成非常小的纳米颗粒，其中一些非常小，无法用经典物理学来理解，但需要使用量子力学。其他（稍大一些，但仍在纳米尺度上）形成纳米晶体，其物理性质可能与那些更熟悉的由大块材料形成的晶体有很大不同。该项目试图通过使用磁性、光学和x射线衍射技术来理解这些差异背后的物理原理。因此，这个项目的智能基础设施有望在未来的某个时候帮助开发新的磁性和磁光纳米器件。不同的任务和项目活动的设计目标是鼓励代表性不足的群体参与科学，为科学基础设施做出贡献，并将科学与教育结合起来。教育/研究项目将允许从高中到研究生水平的学生参与。这些是特别的NSF吗？范德比尔特大学科学拓展中心高中暑期实习。

Technical AbstractThis project aims at determining how geometry and magneto-optical effects are correlated in a class of Heisenberg ferromagnetic nanomaterials, rare earth chalcogenide nanocrystals. Monodisperse nanocrystal of EuS, EuO and EuTe with sizes ranging between less than 2.0 nm (quantum-confined) to about 20 nm (nanocrystals) will be produced using a thermolysis procedure of single source precursor under nitrogen atmosphere. Magnetic and magneto-optical properties of the nanocrystals will be studied as functions of crystal size, crystal boundary characteristics and local atomic separation within the crystals themselves. The studies will be carried out by means of magnetic, optical and x-ray diffraction, techniques. The different tasks and project activities are designed with the goals to encourage the participation of underrepresented groups in science, contribute to science infrastructure and integrate science and education. Educational/research programs will be available to allow the participation of students ranging from high school to graduate level. These are in particular NSF?s Research Experience for Undergraduates (REU) and the Vanderbilt Center for Science Outreach High School Summer Internship. Intellectual infrastructure of this project is expected to aid in the development of new magnetic and magneto-optical nanodevices.Non-technical AbstractNanotechnology continues to produce important and unsuspected results, many of them for the benefit of mankind. Its potential is still being exploited and its development will likely continue within the foreseeable future. As structures and devices become smaller and smaller, the properties of the materials from which they are made change?in many instances dramatically?and differ from the properties of the bulk. Understanding these properties is very important to continue the development of technologies and the understanding of physical phenomena at smaller and smaller scales. On this light, this project aims at determining how geometry and magneto-optical effects are correlated in a class of ferromagnetic nanomaterials: the rare earth chalcogenides. When prepared using the specific methods of this project, these materials form in very small nanoparticles, some of which are so small that cannot be understood using classical physics, but require the use of quantum mechanics. Others (somewhat bigger, but still at the nano scale) form nanocrystals whose physical properties can be vastly different from those more familiar crystals formed by the material in bulk. The project seeks to understand the physics behind these differences by using magnetic, optical and x-ray diffraction, techniques. The intellectual infrastructure of this project is therefore expected to aid in the development of new magnetic and magneto-optical nanodevices sometime in the future. The different tasks and project activities are designed with the goals to encourage the participation of underrepresented groups in science, contribute to science infrastructure and integrate science and education. Educational/research programs will be available to allow the participation of students ranging from high school to graduate level. These are in particular NSF?s Research Experience for Undergraduates (REU) and the Vanderbilt Center for Science Outreach High School Summer Internship.