Cicerone Marcus T, Zhong Qin, Johnson Jerainne, Aamer Khaled A, Tyagi Madhusudan
National Institute of Standards and Technology, Gaithersburg, MD 20899-8543.
J Phys Chem Lett. 2011;2(12):1464-1468. doi: 10.1021/jz200490h.
We show that the short-time behavior of time-resolved fluorescence Stokes shifts (TRSS) are similar to that of the intermediate scattering function obtained from neutron scattering at q near the peak in the static structure factor for glycerol. This allows us to extract a Debye-Waller (DW) factor analog from TRSS data at times as short as 1 ps in a relatively simple way. Using the time-domain relaxation data obtained by this method we show that DW factors evaluated at times ≥ 40 ps can be directly influenced by α relaxation and thus should be used with caution when evaluating relationships between fast and slow dynamics in glassforming systems.
我们表明，时间分辨荧光斯托克斯位移（TRSS）的短时行为与在甘油静态结构因子峰值附近的q处从中子散射获得的中间散射函数的行为相似。这使我们能够以相对简单的方式在短至1皮秒的时间从TRSS数据中提取类似德拜-瓦勒（DW）因子。使用通过这种方法获得的时域弛豫数据，我们表明在≥40皮秒的时间评估的DW因子可能直接受到α弛豫的影响，因此在评估玻璃形成系统中快速和慢速动力学之间的关系时应谨慎使用。
