RIA: Structural Relaxations in Glass-Forming Oxide Melts

RIA：玻璃形成氧化物熔体中的结构松弛

• 批准号: 9008918
• 负责人: John Kieffer
• 金额: $ 7.25万
• 依托单位: University of Illinois at Chicago
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1990
• 资助国家: 美国
• 起止时间: 1990-07-01 至 1993-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9008918&HistoricalAwards=false
• 关键词: RIA; Structural; Relaxations; Glass; Forming

The nature of structural relaxations during the glass formation process will be investigated using the viscous behavior of liquid oxide systems using the Brillouin light scattering technique. A signal in the GHz frequency range, related to a complex modulus, allows direct study of viscoelastic relaxation on an atomistic scale. Processes which reflect in the Brillouin spectrum include cooperative vibrations of larger molecular units, structural rearrangements involving bond breaking and reorientations and momentum exchange between diffusing particles. No mechanical coupling is necessary between the probe and the investigated substance, which eliminates some of the difficulties of high temperature measurements and facilitates the study of viscoelastic phenomena in the glass transition region. The fundamental relation between the experimental observations and the structural characteristics of glass.forming liquids is elucidated by complementary numerical simulations.

玻璃化过程中结构弛豫的性质 形成过程将研究使用粘性 使用布里渊光的液体氧化物系统的行为 散射技术 GHz频率范围内的信号， 与复模量相关，允许直接研究 原子尺度上的粘弹性松弛。 过程 在布里渊频谱中反映的包括合作的 较大分子单位的振动，结构的 涉及键断裂和重定向的重排 和扩散粒子之间的动量交换。 没有 在探针和电极之间需要机械耦合， 调查的物质，这消除了一些 高温测量的困难， 有利于研究粘弹性现象， 玻璃化转变区 之间的基本关系 实验观察和结构 玻璃形成液体的特性阐明了 互补的数值模拟。