Room-temperature growth of epitaxial Fe3O4 films by ion beam deposition

Epitaxial and polycrystalline Fe3O4 films were grown on MgO (100) and Si (100) substrates, respectively, at room temperature by using reactive ion beam deposition. The M-S value of epitaxial Fe3O4 films was around 310 emu/cm3, and was almost independent of thickness from 45 to 195 nm. The M-S value of polycrystalline films showed significant thickness dependence, which might be attributed to the formation of the initial layer. The Verwey transition at 110 K was observed on 195 nm epitaxial films, and decreased significantly with decreasing thickness. The reduction of the Verwey temperature may be related to the residual strain in the film. (C) 2004 American Institute of Physics.