Fe3O4(001) films on Fe(001):: Termination and reconstruction of iron-rich surfaces

High-quality and impurity-free magnetite surfaces with (root 2x root 2)R45 degrees reconstruction have been obtained for the Fe3O4(001) epitaxial films deposited on Fe(001). Based on atomically resolved scanning tunneling microscopy images for both negative and positive sample polarity and density-functional-theory calculations, a model of the magnetite (001) surface terminated with Fe ions forming dimers on the reconstructed (root 2x root 2)R45 degrees octahedral iron layer is proposed.