Numerous current technological advancements depend on the need for new material discoveries. However, understanding reactivity patterns is necessary for designing synthesis methods that lead to new and targeted solids. Scientific advances in synthesis are needed to increase productivity and accelerate the discovery of new materials.

Scientists at the U.S. Department of Energy’s (DOE) Argonne National Laboratory, Northwestern University and The University of Chicago have developed a new method for discovering and creating new crystalline materials containing two or more elements.

Xiuquan Zhou, a postdoc at Argonne and the paper’s first author, said: “Our invention method evolved from research into unconventional superconductors. These are solids with two or more elements, at least one of which is not a metal. And they are not longer able to withstand the passage of electricity at different temperatures – anywhere from colder than outer space to that in my office.

The team’s invention process begins with a solution consisting of two components. One is a highly efficient solvent. Any solids added to the solution dissolve in it and react with it. The alternative is a less potent solvent. However, it is there to adjust how the reaction behaves when other elements are added to generate a new solid. The temperature and ratio of the two components are both adjusted during this tuning. Here, the temperature ranges from 750 to 1300 degrees Fahrenheit, which is pretty high.

Mercouri Kanatzidis, a professor of chemistry at Northwestern with a joint appointment at Argonne, said, “We’re not about improving known materials, but about discovering materials that no one knew about or that theorists even thought existed. With this method we can avoid reaction paths to known materials and follow new paths to the unknown and unpredictable.”

To test, scientists applied their method to crystalline compounds made from three to five elements. Their discovery method yielded 30 previously unknown compounds. Ten of them have structures never seen before.

At the X-ray Science Division’s 17-BM-B of the Advanced Photon Source, a DOE Office of Science user facility in Argonne, and the UChicago ChemMatCARS beamline at 15-ID-D, the scientists made single crystals from some of these new compounds and described their structures.

17-BM-B beamline scientist Wenqian Xu said: “With beamline 17-BM-B from the APS, we were able to track the evolution of the structures for the different chemical phases formed during the reaction process.”

Zhou said, “Traditionally, chemists have invented and made new materials, relying only on knowledge of the starting ingredients and the final product. With the APS data, we were also able to take into account the intermediate products that arise during a reaction.”

Since practically any crystalline material can be processed with this technique, this is just the beginning of what is possible. It can also be used to create different crystal formations. This consists of numerous layers that have multiple layers, a layer that is only one atom thick, and chains of unconnected molecules.

Such unusual structures have different properties and are key to the development of next-generation materials applicable not only to superconductors, but also to microelectronics, batteries, magnets and more.

Magazine reference:

  1. Xiuquan Zhou et al, Discovery of structures and compositions of chalcogenides using mixed fluxes, Nature (2022). DOI: 10.1038/s41586-022-05307-7