Electron doping in magnetic semiconductors

在这个提案中，乔治城大学的Stoll教授将合成和表征纳米结构的电子掺杂磁性半导体。这项工作得到了化学系大分子、超分子和纳米化学项目的支持。研究人员发现了一种既可以制备纳米粒子又可以制备镧系硫系半导体纳米棒的新方法，这种方法很容易用于掺杂研究。这些新材料可能在微电子器件中有有用的应用，并且应该提供这些不寻常材料中电子和磁耦合的重要机械细节。采用分子前驱体溶液热裂解法制备了Eu1-xGdxS材料。通过调整掺杂水平，可以提高铁磁有序温度，x。此外，利用水热合成可以合成Eu2O3纳米线和纳米棒，这些纳米线和纳米棒可以化学转化为EuO纳米材料，保持形貌和单晶结构。该工艺将为形成Gd掺杂EuO材料提供一条途径。本课题将研究电子掺杂（Gd）对磁性半导体EuS和EuO的影响，以及形貌（纳米颗粒直径和纳米线结构）的影响。这个项目涉及磁性半导体的研究，它在数据存储和信息处理方面都有应用。这项工作是化学和物理之间高度交叉的，涉及新型纳米结构磁性材料的合成和表征。该团队涵盖了从高中毕业生到高级研究生的教育阶梯，他们在协作实验室环境中工作。为了充分表征这些材料的特性，我们与巴黎皮埃尔和玛丽居里大学的一个教员建立了新的合作关系。PI还作为公共利益科学的联合主任参与了一些外展项目，向理科生介绍政府的科学政策。

In this proposal, Professor Stoll of Georgetown University will synthesize and characterize nanostructured electron doped magnetic semiconductors. The work is supported by the Macromolecular, Supramolecular and Nanochemistry program in the Division of Chemistry. A new route was discovered to produce both nanoparticles as well as nanorods of lanthanide chalcogenide semiconductors, which is easily adapted for doping studies. These novel materials may have useful applications in microelectronic devices, and should provide important mechanistic details of electronic and magnetic coupling in these unusual materials. Nanoparticles have been prepared by solution thermolysis of molecular precursors to form Eu1-xGdxS materials. The ferromagnetic ordering temperature can be increased by tuning the doping level, x. In addition, using hydrothermal synthesis it is possible to synthesize Eu2O3 nanowires and nanorods that can be chemically converted into EuO nanomaterials maintaining morphology and single crystal structures. This procedure should provide a route to forming Gd doped EuO materials. This proposal will study the effect of electron doping (Gd) on magnetic semiconductors EuS and EuO, as well as the effect of morphology (nanoparticle diameter and nanowire structures).This project involves the study of magnetic semiconductors which have applications in both data storage and information processing. The work is highly interdisciplinary between chemistry and physics, and involves both the synthesis and characterization of novel nanostructured magnetic materials. The team spans the educational ladder from high school seniors to senior graduate students, who work in a collaborative laboratory setting. In order to fully characterize these materials, a new collaboration has been established with a faculty at the University of Pierre and Marie Curie in Paris. The PI is also involved in outreach programs as co-Director of Science in the Public Interest, which introduces science students to science policy in government.