Neutrons piece together 40-year puzzle behind iron-iodide’s mysterious magnetism

Researchers from Georgia Tech and the University of Tennessee–Knoxville uncovered hidden and unexpected quantum behavior in a simple iron-iodide material (FeI2) discovered almost a century ago. The new insights were enabled using neutron scattering experiments and theoretical physics calculations at the Department of Energy’s Oak Ridge National Laboratory. The team’s findings solves a 40-year-old puzzle about the material’s mysterious behavior and could be used as a map to unlock a treasure trove of quantum phenomena in other materials.