Spinodal Decomposition and Tricritical Phenomena

激光光散射将被用来研究凝聚态物理中基本感兴趣的几个现象和过程。它们是：水/醇/油混合物中非对称三临界点附近的临界行为；液体混合物的相分离突然导致热力学不稳定；溶液中生长的二氧化硅分形网络的性质，这些网络是某些玻璃的前体，以及这种网络对液体混合物中相分离和临界现象的影响。测量将使用一种独特的、非常精确的激光光散射仪进行，该仪器由先前的NSF支持开发，测量绝对散射截面及其波矢量依赖关系，直到非常小的散射角。它也被用来测量导致光散射的自发涨落的衰减率。这种联合能力非常有用，因为它提供了热力学极化率、静态长度标度和动态行为的准确结果。这为将动态特性与静态特性相关联的理论提供了严格的测试。

Laser light scattering will be used to study several phenomena and processes that are of basic interest in condensed matter physics. These are: critical behavior near a non-symmetric tricritical point in water/alcohol/oil mixtures; phase separation of liquid mixtures suddenly rendered thermodynamically unstable; the properties of fractal networks of silica grown in solution, which are the precursors of certain glasses, and the effect such networks have on phase separation and critical phenomena in liquid mixtures. The measurements will be carried out using a unique and very accurate laser light-scattering instrument developed with prior NSF support, which measures the absolute scattering cross-section and its wave-vector dependence down to very small scattering angles. It is also used to measure the decay-rate of the spontaneous fluctuations responsible for the scattering of light. This joint capability is very useful since it provides accurate results for thermodynamic susceptibilities, static length scales and dynamic behavior. This provides stringent tests of theories relating dynamic properties to static ones.