Observation of the Verwey transition in thin magnetite films

Abstract

Magnetite (Fe3O4) has attracted much interest due to its unique properties such as the Verwey transition and 100% spin polarization at the Fermi surface. In this study thin films of epitaxial magnetite were grown on MgO and MgAl2O4 substrates using pulsed laser deposition. Previous studies suggested that the Verwey transition is typically not seen for film thicknesses less than 50nm. The existence of a sharp Verwey transition may indicate that the film has properties similar to that of bulk magnetite. We have investigated how stress, antiphase boundaries, imhomogenities, and deviations from stoichiometry affect the Verwey transition in thin films.