The interface formation between different thicknesses of strontium titanate (SrTiO3) or titanium nitride (TiN) with a 2000 Angstrom Fe3O4 film is studied using x-ray absorption spectroscopy (XAS) and x-ray magnetic circular dichroism (XMCD). Our results show that the deposition of 10-50 Angstrom of TiN results in an immediate and substantial removal of oxygen from the near interface region, resulting in the formation of spin-randomizing FeO interlayers. For the deposition of SrTiO3 on Fe3O4, our measurements show only a small deviation from the Fe3O4 characteristic XAS signature, suggesting the limited formation of perhaps only one monolayer of another Fe oxide at the interface. The persistent XMCD signal, however, confirms the preservation of Fe3O4 in its ferromagnetic state.