Surface electronic structure and Verwey-transition of magnetite studied by photoemission spectroscopy



We report on a detailed study of single crystal surfaces with (111) and (100) orientations by means of photoemission spectroscopy (PES). The surfaces were prepared by sputtering, annealing, and post-oxidizing and characterized using LEED, XPS, and STM. The surface electronic structure turns out to be strongly dependent on the surface orientation and preparation conditions. This also holds for more bulk sensitive PES measurements using photons with an energy at the Fe 2p resonance threshold. Thus we conclude that the surface region extends much deeper into the bulk than the topmost atomic layer.