(May 21, 2015) Calculating the energy barrier that keeps liquid water below
zero from immediately turning into ice provides the key to understanding its
ability to be compressed as temperature drops
Water behaves in mysterious ways. Especially below zero,
where it is dubbed supercooled water, before it turns into ice. Physicists have
recently observed the spontaneous first steps of the ice formation process, as
tiny crystal clusters as small as 15 molecules start to exhibit the
recognisable structural pattern of crystalline ice. This is part of a new
study, which shows that liquid water does not become completely unstable as it
becomes supercooled, prior to turning into ice crystals. The team reached this
conclusion by proving that an energy barrier for crystal formation exists
throughout the region in which supercooled water’s compressibility continues to
rise. Previous work argued that this barrier vanished as the liquid gets
colder. These findings have been published in EPJ E by Connor Buhariwalla from
St. Francis Xavier University in Antigonish, Canada and colleagues.