Effects of buffer layer on the electronic properties of half-metallic Fe3O4

Abstract

We have investigated in a systematic way the effect of buffer layer materials on the metal-insulator transition and also on the I–V characteristics of half-metallic Fe3O4 films. Using an electron-beam deposition technique, we have grown 150nm of Fe3O4 films directly on Si(001) substrate, on 20-nm Fe2O3 and 20-nm SiO2 buffer layers. We observed that for a fixed Fe3O4 film thickness, the metal-insulator transition is strongly dependent on the buffer layer materials. From the I–V characteristics, we observed an insulator-like gap structure in the density of states below the transition temperature which disappears gradually with increasing temperature.