No fragile-to-strong crossover in LiCl-H2O solution

作者：Nakanishi Masahiro; Griffin Philip; Mamontov Eugene; Sokolov Alexei P^*

来源：Journal of Chemical Physics, 2012, 136(12): 124512.

DOI：10.1063/1.3697841

Dynamics of water, especially in the temperature range of the "no man's land", remain a mystery. We present detailed study of dynamics in aqueous LiCl solution that is often considered as a model for bulk water. We employ broadband dielectric and light scattering spectroscopy in a broad frequency and temperature range. Our analysis reveals no sign of the fragile-to-strong crossover (FSC) neither in structural relaxation nor in translational motions. Our experimental results combined with a large selection of literature data lead to the clear conclusion-there is no FSC in dynamics of aqueous solutions at T similar to 200-230 K. Instead, our analysis reveals appearance of the so-called excess wing at the high frequency tail of the structural relaxation peak. We discuss the localized nature of the relaxation process that contributes to the excess wing.

• 出版日期2012-3-28