Time Resolved Spectroscopy of Complex Materials

复杂材料的时间分辨光谱

• 批准号: 9710140
• 负责人: Keith Nelson
• 金额: $ 39万
• 依托单位: Massachusetts Institute of Technology
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1997
• 资助国家: 美国
• 起止时间: 1997-08-01 至 2002-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9710140&HistoricalAwards=false
• 关键词: Time; Resolved; Spectroscopy; Complex; Materials

9710140 Nelson The aim of this proposal is to achieve an improved fundamental understanding of the dynamical and structural evolution of amorphous and partially disordered materials. Density dynamics of super cooled liquids in the picosecond through millisecond range will be examined, together with the mode-coupling theoretical predictions of supercooled liquid behavior. Linear and (primarily) nonlinear lattice dynamics in crystals near structural phase transitions will be studied to elucidate anharmonic crystalline potential energy surfaces that dictate phase transition mechanisms as well as the dynamics of phase transitions under the influence of short laser pulses. Measurements will also be conducted on thin film structures using laser generated acoustic waves to carry out a systematic study of adhesion, and to develop a new kind of photoacoustic imaging of patterned films and film-substrate assemblies such as those used in microelectronics. %%% An understanding of condensed materials such as glass forming liquids and sol-gel glasses with viscous liquid guests are of tremendous importance to industries involved with the advancement of various technologies dependent on both bulk and thin film materials applications. For example, this project will develop new techniques that will allow for the first-time a thorough characterization of adhesion mechanics in highly spatially resolved film substrate structures, the study of semiconductor transitions under the influence of short laser pulses, and density dynamics in glass forming liquids that will allow more complete testing of theoretical predictions and additional guidance for theoretical development.

9710140 Nelson 该提案的目的是提高对非晶态和部分无序材料的动力学和结构演化的基本理解。 将研究皮秒到毫秒范围内的过冷液体的密度动力学，以及过冷液体行为的模式耦合理论预测。 将研究接近结构相变的晶体中的线性和（主要）非线性晶格动力学，以阐明决定相变机制的非谐波晶体势能表面以及短激光脉冲影响下的相变动力学。 还将使用激光产生的声波对薄膜结构进行测量，以进行粘附力的系统研究，并开发一种新型的图案薄膜和薄膜基板组件（例如微电子中使用的薄膜-基板组件）的光声成像。 %%% 了解凝聚材料，例如玻璃形成液体和具有粘性液体客体的溶胶-凝胶玻璃，对于涉及依赖于块状和薄膜材料应用的各种技术进步的行业来说非常重要。 例如，该项目将开发新技术，首次对高度空间分辨率的薄膜基板结构中的粘附力学进行全面表征，研究短激光脉冲影响下的半导体转变，以及玻璃成型中的密度动力学液体将允许更完整地测试理论预测并为理论发展提供额外指导。