Controlling self-doping in magnetite with temperature

One of the most abundant iron-containing minerals on Earth, and also the oldest known magnetic material, is magnetite, Fe3O4. Magnetite has applications in many fields, such as the study of paleomagnetism—magnetism in rocks induced at the time of their formation—medicine, and data recording. It was the first known example of a metal that transitions to an insulator, a so-called “Verwey transition,” after the Dutch chemist Evert Verwey, who first recognized the changes in the physical properties of magnetite at the transition.