A team of crystallographers from New York University have made a revolutionary discovery that could change the face of crystallography. Shihao Zang and his fellow researchers went to great lengths. Specifically, they turned their attention to directly observing and controlling non-classical crystallization pathways in binary colloidal systems. It was the microscopy work that revealed an unprecedented, ropelike crystal. They decided to name it “Zangenite,” after the lead researcher’s name.
The study, published in Nature Communications, involved observations and experiments that allowed the team to watch how charged colloidal particles behave under various growth conditions. Shihao Zang and his coauthors—co-authors Sanjib Paul, Cheuk Leung, Michael Chen, Theodore Hueckel, Glen Hocky, and Stefano Sacanna—all found that colloidal crystals form in two phases. Their laboratory work gives new insight into this fascinating energy conversion process. First, shapeless swarms of particles coalesce, then organize into perfect crystalline lattices.
Glen Hocky led thousands of computer simulations to model the growth of these crystals, enhancing the team’s understanding of Zangenite’s unique elongated and hollow shape. He noted that “the channels inside Zangenite are analogous to features in other materials that are useful for filtering or enclosing things inside them.”
The researchers painstakingly compared Zangenite’s structure with over a thousand known natural crystals. Even with all this work, they were unable to secure an appropriate match. This prompted Zang to remark, “We study colloidal crystals to mimic the real world of atomic crystals, but we never imagined that we would discover a crystal that we cannot find in the real world.”
Stefano Sacanna emphasized the significance of their findings, stating that with colloids, it is possible to “watch crystals form with our microscope.” In addition to calling it fantastic news, he seemed enthusiastic about the clear potential for many more discoveries to come. “Before, we thought it would be rare to observe a new crystal structure, but we may be able to discover additional new structures that haven’t yet been characterized,” he explained.
Geometrically and chemically distinct, the new crystal structure—dubbed L3S4—was named for its tetragonal symmetry and composition. This surprising discovery opens up exciting new possibilities for hollow, low-density crystals. In this case, experimental observation and computer modeling combined perfectly. This collaboration allowed the researchers to realize that this particular crystal structure had not been observed before.