Synthesis and Properties of Magnetic Ceramic Nanoparticles

该奖项是根据2009年美国复苏和再投资法案（公法111-5）资助的。非技术描述：本项目将研究磁性陶瓷纳米颗粒，以探索其有趣的物理化学性质及其在催化和气体传感方面的潜在应用。由于这些系统具有与大表面积相关的大活性，因此有望在纳米尺度上增强器件性能。特别是，纳米颗粒形式的溶解度大大大于体积溶解度；其原因尚不清楚。将构建纳米级的相图，因为它们被认为与体相不同。这种方法可以为磁性系统的纳米技术提供真正的突破。参与该项目的学生和博士后将对杜肯大学的基础设施产生重大影响。技术细节：本项目拟合成掺杂锡、钛、锌、铈、铬、锆的磁性纳米颗粒。制备纳米颗粒体系的技术主要有水热合成和机械化学活化。结构和磁性表征将使用Mössbauer光谱、x射线衍射、电子显微镜、磁性测量和热分析进行。该项目首次确定了纳米颗粒体系的溶解度极限，并首次使用基于Mössbauer效应的应用程序来推断混相信息。从这些技术中获得的结构和磁性信息将与传感特性的测量结果有关，以便为选择的应用开发增强型化学传感器的定制特性。该项目将培养在科学前沿工作的本科生，并对当前对固体磁性的理解产生重大影响。

This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).NON-TECHNICAL DESCRIPTION: Magnetic ceramic nanoparticles will be studied in this project to explore their interesting physico-chemical properties and their prospective applications in catalysis and gas sensing. Enhanced device performance is expected for these systems at the nanoscale, due to their large activity associated with their large surface areas. In particular, the solubility in the form of nanoparticles is considerably greater than the bulk solubility; the reasons for that are not yet understood. Phase diagrams at the nanoscopic levels will be constructed, as they are believed to be different from those of the bulk. This approach could provide a veritable breakthrough in the nanotechnology of magnetic systems. The students and the post-doctoral fellow involved in this project will make a significant impact on the infrastructure at Duquesne University.TECHNICAL DETAILS: The project proposes the synthesis of magnetic nanoparticles doped with tin, titanium, zinc, cerium, chromium and zirconium. The techniques used to prepare the system of nanoparticles are hydrothermal synthesis and mechanochemical activation. The structural and magnetic characterization will be performed using Mössbauer spectroscopy, X-ray diffraction, electron microscopy, magnetic measurements and thermal analysis. This project determines for the first time the solubility limits of a system of nanoparticles and it uses for the first time an application based on the Mössbauer effect to infer information about miscibility. The structural and magnetic information derived from these techniques will be related to results of measurements of the sensing properties, in order to develop tailored characteristics of enhanced chemical sensors for select applications. This project will train undergraduate students who will work at the frontiers of science and have a significant impact on the current understanding of magnetism in solids.