Effects of buffer layer on the electronic properties of half-metallic Fe 3O 4

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 Fe3 O4 films. Using an electron-beam deposition technique, we have grown 150 nm of Fe3 O4 films directly on Si(001) substrate, on 20-nm Fe2 O3 and 20-nm Si O2 buffer layers. We observed that for a fixed Fe3 O4 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. © 2005 American Institute of Physics.