Supercooled liquids: Clearing the water

Ken-ichiro Murata and Hajime Tanaka have found the evidence of a transition between two coexisting liquids of the same composition in a water-glycerol mixture, where glycerol prevents the crystallization of water, provides a unique link to an elusive liquid-liquid transition in pure water. Detailed microscopy experiments conducted in Tanaka's laboratory at different temperatures have shown that, just as in the common case of near-critical liquid-gas transitions and liquid-liquid transitions, the transition process can occur by either the discrete mechanism of nucleation and growth, or uniform spinodal decomposition. Their work represents a distinctive approach to the elusive LLT in pure water, if the transition is indeed isocompositional. The authors have also deduced that the transition is isocompositional from the observation that ice crystals eventually form in the residual liquid, defined as the low-density liquid that forms at low temperature.