Growth of Fe$_3$O$_4$ films on the Si(111) surface covered by a thin SiO$_2$ layer

Magnetite polycrystalline films are grown by variously oxidizing a Fe film on the Si(111) surface covered by a thin (1.5 nm) SiO$_2$ layer. It is found that defects in the SiO$_2$ layer influence silicidation under heating of the Fe film. The high-temperature oxidation of the Fe film results in the formation of both Fe$_3$O$_4$ and iron monosilicide. However, the high-temperature deposition of Fe in an oxygen atmosphere leads to the growth of a compositionally uniform Fe$_3$O$_4$ film on the SiO$_2$ surface. It is found that such a synthesis method causes [311] texture to arise in the magnetite film, with the texture axis normal to the surface. The influence of the synthesis method on the magnetic properties of grown Fe$_3$O$_4$ films is studied. A high coercive force of Fe$_3$O$_4$ films grown by Fe film oxidation is related to their specific morphology and compositional nonuniformity.