Evolution of the structural and magnetotransport properties of magnetite films depending on the temperature of their synthesis on the SiO2/Si(001) surface

Resumo

The methods of transmission and reflection electron diffraction have been used to investigate the structure of Fe₃O₄ films depending on the temperature of their synthesis on an Si substrate coated with an ultrathin layer of SiO₂. The thus-grown polycrystalline films of magnetite had a texture, the axis of which was perpendicular to the surface of the SiO₂ film. It has been revealed that, with an increase in the growth temperature, a structural rearrangement occurs which is characterized by an increase in the volume fraction of grains with the preferred (311) orientation. A study of the magnetotransport properties of the films has shown that the magnitude of their magnetoresistance increases with an increase in the temperature of their synthesis. It has been established that in the Fe₃O₄/SiO₂/Si system with a tunneling-thin layer of SiO₂ the magnetoresistance decreases as a result of the flow of an electric current through the silicon substrate.