A Low-Temperature Amorphous Phase in a Fragile Glass-Forming Substance

We have observed what appears to be a first-order phase change from deeply supercooled liquid triphenyl phosphite at 1 atm to a rigid, “apparently” amorphous phase which we denote as the “glacial phase”. This is a new, crisper, and rather different addition to the examples of polyamorphism that have recently been studied. In order to “deeply” supercool the liquid, it must be quick-quenched to a low temperature:  if heated slowly, but immediately, it crystallizes; if allowed to stand for several hours at low temperature, it transforms to the glacial phase; and if subsequently heated it, too, crystallizes, but at a higher temperature than that for liquid crystallization. The glacial phase can be clearly distinguished from both the normal crystal and the ordinary glass. We propose a model for the formation of this “apparently” amorphous glacial phase.