Time-Resolved EELS of Photonic Crystals and Glasses

光子晶体和玻璃的时间分辨 EELS

• 批准号: 0603993
• 负责人: Nan Jiang
• 金额: $ 52.07万
• 依托单位: Arizona State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-07-15 至 2011-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0603993&HistoricalAwards=false
• 关键词: Time; Resolved; EELS; Photonic; Crystals

NON-TECHNICAL DESCRIPTION: Glasses consisting primarily of Ge, As, S, Se and Te (chalcogenides) constitute an important class of optical materials that can potentially enable a wide range of modern technologies including photonics, telecommunication, sensors and memory devices. However, successful compositional design of chalcogenides with optimized properties tailored for these technological applications needs formulation of accurate predictive models, which in turn requires fundamental data on the atomic structure and dynamics of these materials. This research program aims to use state-of-the-art experimental and simulation methods to study the atomic structure and to investigate dynamical phenomena in these glasses and in the liquids from which they derive. These results will be used to formulate and test models linking the microscopic structure and dynamics with the macroscopic properties, which will play key role in smart compositional engineering of these materials. Students in this research program will learn to investigate problems in the realm of "basic science" that underlies industrial applications. The use of experimental facilities at the Argonne National Laboratory (ANL) will enrich the graduate education and training experience through participation in a unique research environment and will foster intellectual exchange. This program will coordinate with the underrepresented minority-serving and K-12 outreach programs on campus to attract and recruit underrepresented graduate students and to increase the awareness of students in the science and technology of glassy materials. TECHNICAL DETAILS: This program seeks to study the structure-property relationships and to develop an atomic scale understanding of the structural mechanisms of transport and relaxation near the glass transition (Tg) in complex chalcogenide glasses in the Ge-As-S-Se-Te system. A combination of neutron/x-ray diffraction and Reverse Monte Carlo modeling will be used to obtain an unusually complete picture of the intermediate-range atomic structures of these materials for the first time. The temperature induced structural changes and the dynamics of exchange among structural species in these glasses and parent liquids will be characterized in situ with 77Se and 125Te nuclear magnetic resonance (NMR) spectroscopy at temperatures near and above Tg, and ex situ, on samples with different time-temperature histories by a combination of NMR and Raman spectroscopic techniques. These results will be used to develop predictive models, linking the atomic structure and dynamics with macroscopic physical properties, which are crucial for compositional optimization of these materials for a wide range of technological applications. This work includes significant training of graduate students in state-of-the-art spectroscopic, diffraction and simulation techniques.

非技术描述：主要由GE组成的眼镜，AS，S，SE和TE（Chalcogenides）构成了一类重要的光学材料，可以潜在地实现广泛的现代技术，包括光子学，电信，传感器，传感器和记忆设备。但是，针对这些技术应用量身定制的优化特性的葡萄干区的成功组成设计需要准确的预测模型的制定，这又需要有关这些材料原子结构和动态的基本数据。 该研究计划旨在使用最先进的实验和仿真方法研究原子结构，并研究这些眼镜和它们得出的液体中的动力学现象。这些结果将用于制定和测试将显微镜结构和动力学与宏观特性联系起来的模型，该特性将在这些材料的智能组成工程中起关键作用。 该研究计划中的学生将学习研究基础工业应用“基础科学”领域的问题。 Argonne国家实验室（ANL）的实验设施的使用将通过参与独特的研究环境来丰富研究生教育和培训经验，并将促进知识交流。该计划将与校园内代表性不足的少数族裔服务和K-12外展计划进行协调，以吸引和招募代表性不足的研究生，并提高学生在玻璃材料科学和技术方面的认识。 技术详细信息：该计划旨在研究结构 - 特性关系，并在GE-AS-SSE-te系统中复杂的Chalcogenide玻璃杯中对玻璃转变（TG）附近的运输和放松的结构机制进行原子规模的理解。 中子/X射线衍射和反向蒙特卡洛建模的结合将首次获得这些材料中间范围的原子结构的异常完整的图像。 这些眼镜和家长液体中结构物种之间的结构变化和交换的动态将在TG附近和上方的温度附近和上方的77SE和125TE核磁共振（NMR）光谱上进行特征，而在TG的温度下，在具有不同时间播种的样品上，通过NMR和Raman Experropopopic Techiquersequessiquesiquessiquessiquessiquessiques。 这些结果将用于开发预测模型，将原子结构和动力学与宏观物理特性联系起来，这对于对这些材料的组成优化至关重要。这项工作包括对研究生进行最先进的光谱，衍射和仿真技术的大量培训。