Following the Crystallization of Amorphous Ice after Ultrafast Laser Heating

Using time-resolved wide-angle X-ray scattering, we investigated the early stages (10 mu s-1 ms) of crystallization of supercooled water, obtained by the ultrafast heating of high- and low-density amorphous ice (HDA and LDA) up to a temperature T = 205 K +/- 10 K. We have determined that the crystallizing phase is stacking disordered ice (I-sd), with a maximum cubicity of chi = 0.6, in agreement with predictions from molecular dynamics simulations at similar temperatures. However, we note that a growing small portion of hexagonal ice (I-h) was also observed, suggesting that within our timeframe, I-sd starts annealing into I-h. The onset of crystallization, in both amorphous ice, occurs at a similar temperature, but the observed final crystalline fraction in the LDA sample is considerably lower than that in the HDA sample. We attribute this discrepancy to the thickness difference between the two samples.

Automated summary

Using time-resolved wide-angle X-ray scattering, this study investigated the early stages of crystallization of supercooled water. It was found that the crystallizing phase is stacking disordered ice, with a small portion of hexagonal ice also observed. The final crystalline fraction in low-density amorphous ice was considerably lower than that in high-density amorphous ice.