Nanotechnology: Preparation, Characterization, and Dynamical Properties of Nanostructured Metal-Oxide Materials

纳米技术：纳米结构金属氧化物材料的制备、表征和动力学性能

• 批准号: 9871864
• 负责人: Brian Tissue
• 金额: $ 51.65万
• 依托单位: Virginia Polytechnic Institute and State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1998
• 资助国家: 美国
• 起止时间: 1998-09-01 至 2003-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9871864&HistoricalAwards=false
• 关键词: Nanotechnology; Preparation; Characterization; Dynamical; Properties

9871864 Tissue A systematic and extensive study of the physical, optical, and dynamical properties of lanthanide-doped metal-oxide nanostructures will be performed. These novel materials have potential applications as materials for lasers and optical amplifiers, and as phosphors for flat-panel displays. This work will assist in developing a theoretical and practical framework to optimize the optical properties of metal-oxide nanocrystals and nanocomposites. A reduction in particle size for micron-size materials has often resulted in a reduction in optical emission due to quenching by surface defects. There are experimental indications that finite size effects in nanocrystals can significantly enhance the oscillator strength of impurity transitions. In addition, modifications to the phonon density-of-states, and to the strength of the electron-phonon interaction, will undoubtedly influence non-radiative relaxation rates in nanoparticle systems. Applications in the display industry require smaller particle size for both high-resolution and low voltage flat-panel displays. At the same time, they also require rugged and high-efficiency materials. Therefore, the optical and dynamical properties of the nanocrystals will be characterized both alone and after passivation by surface modification or by embedding in a matrix. The approach will be to prepare nanostructured materials, and characterize their structure and morphology by X-ray diffraction, transmission-electron microscopy, atomic-force microscopy, and fluorescence spectroscopy at Virginia Tech. Well-characterized nanostructured materials will then be studied at the University of Georgia using high-resolution spectroscopic techniques to determine how fundamental properties such as oscillator strength, optical dephasing, non-radiative relaxation, phonon dynamics, and energy-transfer processes depend on particle size or surface modification. The collaboration between Virginia Tech and the University of Georgia brings together expertise in nanocrystalline synthesis, processing, and characterization, with expertise in high resolution and nonlinear spectroscopic techniques. The close collaboration between synthesis and spectroscopy groups will allow the PIs to systematically grow and characterize new materials, with property measurements providing rapid feedback to guide material preparation and processing. The synergism of this collaboration will allow much more progress in preparing and understanding very complex nanostructures than if the groups were working alone %%% Novel lanthanide-doped metal-oxide nanostructured materials have potential applications as materials for lasers and optical amplifiers, and as phosphors for flat-panel displays. The results of this research will provide feedback to engineer nanostructures to improve the properties of these materials. The interdisciplinary nature of the collaboration between Virginia Tech and the University of Georgia will provide an excellent educational experience to train future scientists for the multidisciplinary teamwork that is increasingly characteristic of scientific research and technological development. This project is funded as part of Nanotechnology Initiative by the Ceramics and the Solid State Chemistry programs in the Division of Materials Research, the Physical Foundations and Enabling Technologies program in the Division of Electrical and Communication Systems, and the Office of Multidisciplinary Activities in the Mathematical and Physical Sciences Directorate. In addition, the Division of International Programs has provided funding for travel in order for the PIs to perform collaborative research with their counterparts in Russia.

小行星9871864 本论文将对镧系元素掺杂的金属氧化物纳米结构的物理、光学和动力学性质进行系统而广泛的研究。 这些新材料作为激光器和光放大器的材料以及作为平板显示器的磷光体具有潜在的应用。 这项工作将有助于开发一个理论和实践框架，以优化金属氧化物纳米晶体和纳米复合材料的光学性能。 由于表面缺陷的猝灭，微米尺寸材料的粒度减小通常导致光发射的减少。 实验表明，纳米晶体中的有限尺寸效应可以显著增强杂质跃迁的振子强度。 此外，修改的声子密度的状态，电子-声子相互作用的强度，无疑会影响纳米粒子系统的非辐射弛豫速率。 显示器工业中的应用需要更小的颗粒尺寸用于高分辨率和低电压平板显示器。 同时，它们还需要坚固耐用的高效材料。 因此，纳米晶体的光学和动力学性质将被表征为单独和通过表面改性或通过嵌入基质钝化后。 该方法将是制备纳米结构材料，并在弗吉尼亚理工大学通过X射线衍射，透射电子显微镜，原子力显微镜和荧光光谱来表征其结构和形态。 然后，格鲁吉亚大学将使用高分辨率光谱技术研究表征良好的纳米结构材料，以确定基本特性，如振子强度，光学退相，非辐射弛豫，声子动力学和能量转移过程如何取决于颗粒大小或表面改性。弗吉尼亚理工大学和格鲁吉亚大学之间的合作汇集了纳米晶体合成、加工和表征方面的专业知识，以及高分辨率和非线性光谱技术方面的专业知识。 合成和光谱学小组之间的密切合作将使PI能够系统地生长和表征新材料，性能测量提供快速反馈，以指导材料制备和加工。 这种合作的协同作用将允许更多的进展，在制备和理解非常复杂的纳米结构比如果小组单独工作%新型镧系元素掺杂的金属氧化物纳米结构材料有潜在的应用作为激光器和光学放大器的材料，并作为荧光粉的平板显示器。 这项研究的结果将为工程纳米结构提供反馈，以改善这些材料的性能。 弗吉尼亚理工大学和格鲁吉亚大学之间的合作的跨学科性质将提供一个很好的教育经验，培养未来的科学家的多学科团队合作，这是越来越多的科学研究和技术发展的特点。 该项目作为纳米技术倡议的一部分，由材料研究部的陶瓷和固态化学计划，电气和通信系统部的物理基础和使能技术计划以及数学和物理科学理事会的多学科活动办公室资助。 此外，国际方案司还提供旅费，以便PI与俄罗斯同行进行合作研究。