Diffusion dynamics of water molecules in a LiCl solution: a low-temperature crossover.

A quasielastic neutron scattering experiment probing the dynamics of water molecules on the pico- to nanosecond time scale in an aqueous solution of lithium chloride has detected a crossover at about 220-230 K between the high-temperature non-Arrhenius and low-temperature Arrhenius behavior. This is the first experiment where the crossover in the dynamics of water molecules is detected in bulk rather than in confinement. The results suggest that the dynamic crossover observed in the current and many recent experiments is not linked to the specific properties of water; instead, it may represent a more general dynamic transition.