For nearly a decade, the nature of low-density amorphous ice (LDA) has been a topic of debate. Now, researchers from University College London and Cambridge University have provided conclusive evidence that LDA ice is not a true glass, but rather a mixture of crystalline and disordered regions.
Using numerical simulations and lab experiments, Michael Davies and his colleagues found that the resulting “ice cubes” had varying degrees of crystallinity. The team analyzed x-ray diffraction patterns to determine which samples best represented real-world LDA ice. They discovered that those with 16-19% crystallinity provided the most accurate match.
In a surprise twist, the researchers created their own LDA ice samples and found that they adopted crystalline structures, even after being warmed to 0°C. This “memory effect” suggests that LDA ice contains hidden crystalline regions. The findings raise important questions about our understanding of liquid water and its transformation into glassy materials.
The study’s authors now aim to investigate whether it is possible to create a truly amorphous ice, shedding light on the fundamental nature of this enigmatic substance.
Source: https://physics.aps.org/articles/v18/s86