Fe3O4(1 1 1) thin films with bulk-like properties: growth and atomic characterization

Growth defects, domain structures and off-stoichiometric compositional deviation are the cause of significant deviation of magnetic and transport properties of magnetite (Fe3O4) thin films. We show that these anomalous properties can be fully controlled by postannealing in CO/CO2 atmosphere. Aberration corrected electron microscopy has revealed a full structural transformation from Fe/FeO x to Fe3O4 and a drastic reduction of growth defects in the postannealed films. The magnetic and magnetotransport measurements show that postannealed film properties are bulk-like: the magnetization was fully saturated with ∼480 emu cm−3, as in bulk single crystal, and the negative magnetoresistance was suppressed by an order of magnitude.