Description
Water is ubiquitous and the most important liquid for life on earth. Although the water molecule is seemingly simple, various macroscopic properties of water are most anomalous. It was suggested that the anomalous behaviour of ambient and supercooled water can be explained by a two-state model of water. An important role in this ongoing debate plays the amorphous forms of water. Since the discovery of two distinct amorphous states of ice with different density (high- and low-density amorphous ice, HDA and LDA) it has been discussed whether and how this phenomenon of polyamorphism at high pressures is connected to the occurrence of two distinct liquid phases (HDL and LDL). The glass-to-liquid transition of the two states is still not fully understood (1). While experimental determination of the glass transition at elevated pressure and cold temperatures is technically difficult to implement, measurements on water and amorphous ices are even more challenging, as the glass transition is interrupted by crystallization. In my talk I will give an overview about recent XFEL experiments (2) as well as X-ray photon correlation spectroscopy (XPCS) on amorphous ices. The experiments are done at ambient pressure conditions (3) as well as elevated pressure using a diamond anvil cell(4).
(1) K. Amann-Winkel et al., Rev. Mod. Phys. 88, 0110002 (2016)
(2) K. Amann-Winkel et al., Nat. Comm., 14, 442 (2023)
(3) Hailong Li et al., JPCL (2023) 14, 49
(4) Aigerim Karina et al., Comms.Chem. (2025) 8:82
