Minerals in the soil under our feet constantly undergo chemical reactions. But we still don’t understand exactly how many of those interactions happen. Now, Kevin Rosso, Sandra Taylor, and coworkers at Pacific Northwest National Laboratory have used the imaging technique atom probe tomography to study the way the mineral goethite interacts with its surroundings (Proc. Natl. Acad. Sci. U.S.A. 2019, DOI: 10.1073/pnas.1816620116). Goethite is abundant in soil and is a major component of rust. The researchers found that tracer iron atoms didn’t merely stick to the surface of goethite; they also penetrated more than 3 nm into the mineral structure, concentrating at “hot spots” where there were flaws in the material. The scientists hope that knowledge like this could one day lead to a better understanding of how goethite can be used to bind heavy metals in soil to decontaminate it.
Music: “Loopster” by Kevin MacLeod is licensed under CC BY 3.0.