Zinc snowflakes crystallize from a sea of liquid metal

What better way to demonstrate new crystallization techniques than to make snowflakes? But instead of making delicate crystals of water, researchers from the University of New South Wales, the University of Auckland, and Victoria University of Wellington sprouted tiny zinc snowflakes out of liquid gallium (Science 2022, DOI: 10.1126/science.abm2731).

The team added 10% by weight of Zn to Ga, melted the two metals together, and let the alloy cool. The structural variety of the resulting crystals, shown in these scanning electron micrographs, comes from different cooling temperatures and times, says materials scientist and study author Nicola Gaston of the University of Auckland, and “demonstrates enormous promise for further fine-tuning of structural control.” The group also showed that the method works for crystallizing other metals, including copper, platinum, and tin.