Homogeneous nucleation and glass transition temperatures in solutions of Li salts in D₂O and H₂O. Doubly unstable glass regions

Various lithium salt solutions in water and D₂O have been studied to determine the regions of composition in which bulk samples can be vitrified during cooling, and also those regions in which even micron-size samples cannot be prevented from crystallizing. The respective glass transition temperatures and homogeneous nucleation temperatures have been determined. There is an interesting intermediate region where, at normal cooling rates, bulk samples fail to nucleate at the expected temperature due, evidently, to slow growth of critical fluctuations. In this region samples may be obtained as glasses which have a special instability toward crystallization. These are of much interest since they provide a means of studying the poorly understood homogeneous nucleation phenomenon in bulk samples under conditions in which the process can be promoted, and also arrested for study, at will.